Rick Griffin Paintings & Artwork for Sale | Rick Griffin Art Value Price Guide

Aug. 20, 2026
[PSYCHEDELIC ART POSTER]. [GRIFFIN, Rick (1944-1991), artist]. Joint Show. A Rare Blend. [California]: Calif. Litho Plate, 1967.
Est: $400 - $600
[PSYCHEDELIC ART POSTER]. [GRIFFIN, Rick (1944-1991), artist]. Joint Show. A Rare Blend. [California]: Calif. Litho Plate, 1967. Rare large full color poster for a a psychedelic art exhibition featuring art by Wes Wilson, Stanley Mouse and Alton Kelley (misspelled by Griffin), Victor Moscoso and Griffin. Image depicts a cigarette box with marijuana joints sticking out of the top. Approximately 28 x 22". Unbacked. STATED FIRST EDITION, ONE OF 1,200 COPIES. The exhibition took place in San Francisco's Moore Gallery in July of 1967.
Potter & Potter Auctions Inc.
Jun. 25, 2026
GRIFFIN, Rick (1944-1991). Grateful Dead / Honolulu International Center Arena. 1982.
Est: $200 - $300
GRIFFIN, Rick (1944-1991). Grateful Dead / Honolulu International Center Arena. 1982. Hawaiian Aoxomoxoa. [Second Printing] of the 1968 concert poster for the canceled July 1968 show of Grateful Dead with It's a Beautiful Day and Theater of Madness at the H.I.C. Exhibition Center in Honolulu, HI. Paper. Highly sought-after design featuring psychedelic imagery indicative of the Dead. 20 x 12 ¼”.
Potter & Potter Auctions Inc.
Mar. 26, 2026
GRIFFIN, Rick (1944-1991). Grateful Dead / Honolulu International Center Arena. 1982. Hawaiian Aoxomoxoa. [Second Printing] of the 1968 concert poster for the canceled July 1968 show of Grateful Dead
Est: $200 - $300
GRIFFIN, Rick (1944-1991). Grateful Dead / Honolulu International Center Arena. 1982. Hawaiian Aoxomoxoa. [Second Printing] of the 1968 concert poster for the canceled July 1968 show of Grateful Dead with It's a Beautiful Day and Theater of Madness at the H.I.C. Exhibition Center in Honolulu, HI. Paper. Highly sought-after design featuring psychedelic imagery indicative of the dead. A. light edgewear. 20 x 12 ¼”.
Potter & Potter Auctions Inc.
Jul. 17, 2025
Rick Griffin puffing Kief poster
Est: $200 - $300
Heading: Author: Griffin, Rick Title: A Puff of Kief in the Morning Makes a Man as Strong as a Hundred Camels in the Courtyard Place Published: Berkeley, CA Publisher:Berkeley Bonaparte Date Published: 1967 Description: Offset-printed poster. 49.5x35 cm (19½x14½"). Second printing of this head shop poster, the first to be printed in color.
PBA Galleries Auctions & Appraisers
Jun. 24, 2025
RICK GRIFFIN, Californian Poster
Est: $200 - $400
RICK GRIFFIN Californian Poster lithograph with printed text in image 42.5 x 34cm
Gibson's
Jun. 05, 2025
GRIFFIN, Rick (American, 1944-1991). Untitled. [Ca. 1980s-1...
Est: $1,000 - $2,000
GRIFFIN, Rick (American, 1944-1991). Untitled. [Ca. 1980s-1991]. Airbrush/stencil on illustration board, signed by Griffin on lower left corner. #38/60. Approximately 15 x 20”. Fine. Image of a flaming eyeball over the desert by this famous rock album cover artist.
Potter & Potter Auctions Inc.
Feb. 11, 2025
Rick Griffin (1944-1991) Group of Vintage Advertising Art (10 Works)
Est: $1,500 - $3,000
Rick Griffin (American, 1944-1991) Group of Vintage Advertising Art (10 Works). Framed. Sizes Ranging From: 4.75'' x 4.75'', 12 x 12 cm (sight); 10.25'' x 10.25'', 26 x 26 cm (frame) To: 12.75'' x 8.5'', 32 x 22 cm (sight); 19.5'' x 15.25'', 50 x 39 cm (frame). Ex. Clearlight Collection, Los Angeles, CA.
Material Culture
Feb. 11, 2025
Rick Griffin (American, 1944-1991) 2 Works
Est: $300 - $500
Rick Griffin (American, 1944-1991) 2 Works, one signed. Both framed. Sizes: 1) 15.5'' x 11'', 39 x 28 cm (sight); 22.25'' x 17.75'', 57 x 45 cm (frame); 2) 26.5'' x 18.25'', 67 x 46 cm (sight); 33.25'' x 25'', 84 x 64 cm (frame). Ex. Clearlight Collection, Los Angeles, CA.
Material Culture
Oct. 06, 2024
RICHARD "RICK" GRIFFIN, QUICKSILVER MESSENGER SERVICE, "ETERNAL RESEVOIR", POSTER
Est: $200 - $250
Artist: Richard "Rick" Griffin, American (1944 - 1991) Title: Quicksilver Messenger Service, "Eternal Resevoir" Year: 1968 Medium: Poster Size: 29 x 20 in. (73.66 x 50.8 cm) Publisher: Family Dog Productions, San Francisco Description: This poster was created by American artist Rick Griffin for the band "Quicksilver Messenger Service".
RoGallery
Aug. 05, 2024
Charlatans & Jook Savages Medicine Show Concert Poster, Rick Griffin, 1967
Est: $200 - $300
Medicine Show-Showdown Between Bands. Artist: Rick Griffin (American, 1944-1991). Double concert program. Original first printing concert poster for CHARLATANS and the OLD GREY ZIPPER. Color offset lithograph poster. Publisher: Berkeley Bonaparte. Venue: Irwin Street Warehouse, San Raphael, California. Date: May 12-13 1967. Dimensions: 14 inches x 20 inches. Condition: overall good condition, restoration to corners, toned, tape residue on verso noted and outer pin holes. Provenance: private estate.
Kensington Estate Auctions
Jul. 11, 2024
Rick Griffin Family Dog poster, Denver
Est: $200 - $300
Heading: Author: Griffin, Rick Title: [Denver Opening] Big Brother and the Holding Company / Blue Cheer Place Published: San Francisco Publisher:Family Dog Date Published: 1967 Description: Offset-printed poster on uncoated index stock. 50.4x71 cm (19¾x28”). One of 2000 printed.Double size Rick Griffin poster printed for the concert held in Denver Colorado on September 8-9, 1967, the first Family Dog show in Denver. King: FD-79-OP-2.
PBA Galleries Auctions & Appraisers
Jun. 06, 2024
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Est: $40 - $60
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Lawsons
May. 30, 2024
Rick Griffin, Big Brother and the Holding Company, Bill Graham Presents at Fillmore, 1968, Poster, 80 x 51 cm, frame 95.5 x 66 cm
Est: $200 - $300
Rick Griffin Big Brother and the Holding Company, Bill Graham Presents at Fillmore, 1968 Poster © 1968 Bill Graham Tea Lautrec Litho
Lawsons
May. 30, 2024
Rick Griffin, The Doors, Family Dog Denver, 1967, Poster, 54 x 32 cm, frame 69 x 46 cm
Est: $200 - $300
Rick Griffin The Doors, Family Dog Denver, 1967 Poster © 1967 Family Dog Production
Lawsons
May. 30, 2024
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Est: $40 - $60
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Lawsons
May. 16, 2024
GRIFFIN, Rick (1944 – 1991). Bulls Eye / Albert King / Cred...
Est: $300 - $500
GRIFFIN, Rick (1944 – 1991). Bulls Eye / Albert King / Creedence Clearwater Revival / Fillmore West. San Francisco: Tea Lautrec Litho, 1968. Bill Graham #137. First and only printing. 14 x 22”. Unbacked. Slightest creases at lower corners. A/A-.
Potter & Potter Auctions Inc.
Apr. 27, 2024
Large Rick Griffin Original Ink Illustration Art
Est: $2,000 - $4,000
California,1944-1991 An incredible find from a local Rhode Island estate. An original Rick Alden Griffin AKA "Quicksilver Rick" ink drawing on heavy weight illustration paper. Intricate phantasmal composition of various characters over a night sky with large rattle snake at the center of the image. Notice the fine stippling throughout the work. Signed and dated lower right "Quicksilver Rick 73...".
Bruneau & Co. Auctioneers
Mar. 15, 2024
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Est: $40 - $60
1991 Rick Griffin Rock Art Opening No.1, including Jimi Hendrix etc. brochure, the frame 42 x 34.5 cm
Lawsons
Mar. 15, 2024
Rick Griffin, Retrospectacle Bay Area Celebrates Psychedelia, 1987, San Francisco Arts Commission Gallery, Poster, 59 x 41 cm, frame 77.5 x 60 cm
Est: $100 - $200
Rick Griffin Retrospectacle Bay Area Celebrates Psychedelia, 1987, San Francisco Arts Commission Gallery Poster
Lawsons
Mar. 15, 2024
Rick Griffin & Alton Kelley , KSAN Radio Station Promo Poster, San Francisco 1969, Poster, 73 x 50 cm, frame 83 x 64 cm
Est: $150 - $250
Rick Griffin & Alton Kelley KSAN Radio Station Promo Poster, San Francisco 1969 Poster In heavy glass frame
Lawsons
Mar. 15, 2024
Rick Griffin, Presenting The New Improved Psychedlic Shop Featuring the 1st Anniversary Jook Savage Art Show, 1967, Poster, 46. 5 x 34 cm, frame 61 x 49 cm
Est: $100 - $200
Rick Griffin Presenting The New Improved Psychedlic Shop Featuring the 1st Anniversary Jook Savage Art Show, 1967 Poster © Distributed by Berkeley Bonaparte 1967
Lawsons
Mar. 15, 2024
Rick Griffin, The Family Dog Quicksilver 1967 Avalon Ballroom, comic strip style, Poster, 51 x 33 cm, frame 63 x 47 cm
Est: $100 - $200
Rick Griffin The Family Dog Quicksilver 1967 Avalon Ballroom, comic strip style Poster © Family Dog Productions
Lawsons
Mar. 15, 2024
Rick Griffin, Grateful Dead Sons of Champlin Initial Shock 1969, Avalon Ballroom, 67 x 54 cm, frame 82 x 69 cm
Est: $150 - $250
Rick Griffin Grateful Dead Sons of Champlin Initial Shock 1969, Avalon Ballroom © 1982 Jose's Late Nite Final Inscribed Rick Griffin, 1969
Lawsons
Mar. 15, 2024
Rick Griffin, Quicksilver Messenger Service, Kaleidoscope, Avalon Ballroom, 50 x 34 cm, frame 64 x 49 cm
Est: $100 - $200
Rick Griffin Quicksilver Messenger Service, Kaleidoscope, Avalon Ballroom © 1968 Family Dog Productions
Lawsons
Mar. 15, 2024
Rick Griffin, Pinnacle Presents AMA Jimi Hendrix Experience 1968 Shrine Auditorium, Poster, 54.5 x 34 cm, frame 69 x 49 cm
Est: $150 - $250
Rick Griffin Pinnacle Presents AMA Jimi Hendrix Experience 1968 Shrine Auditorium Poster Poster features gorgeous psychedelic art by Griffin that originally appeared in "Zap Comix"
Lawsons
Mar. 15, 2024
Rick Griffin, Jimi Hendrix Experience, the "Flying Eyeball" 1968, ft. John Mayall and the Bluesbreakers, Albert King, presented by Bill Graham, Fillmore Auditorium, San Francisco, Lithograph poster, 54 x 34 cm, frame 68
Est: $600 - $800
Rick Griffin Jimi Hendrix Experience, the "Flying Eyeball" 1968, ft. John Mayall and the Bluesbreakers, Albert King, presented by Bill Graham, Fillmore Auditorium, San Francisco Lithograph poster © 1968 Bill Graham, Tea Lautrec Litho
Lawsons
Mar. 15, 2024
Rick Griffin, Joint Show, A Rare Blend, Wes Wilson, Mouse, Kelly, 1967, Lithograph poster, 69 x 54 cm, frame 84 x 69 cm
Est: $100 - $200
Rick Griffin Joint Show, A Rare Blend, Wes Wilson, Mouse, Kelly, 1967 Lithograph poster © Rick Griffin, 1967 Calif litho plate
Lawsons
Mar. 15, 2024
Rick Griffin, The Doors, Family Dog Denver, 1967, Poster, 54 x 32 cm, frame 69 x 46 cm
Est: $200 - $300
Rick Griffin The Doors, Family Dog Denver, 1967 Poster © 1967 Family Dog Production
Lawsons
Mar. 15, 2024
Rick Griffin, Big Brother and the Holding Company, Bill Graham Presents at Fillmore, 1968, Poster, 80 x 51 cm, frame 95.5 x 66 cm
Est: $200 - $300
Rick Griffin Big Brother and the Holding Company, Bill Graham Presents at Fillmore, 1968 Poster © 1968 Bill Graham Tea Lautrec Litho
Lawsons
Mar. 15, 2024
Rick Griffin, Jimi Hendrix Experience Buddy Miles Express and Dino Valentini etc Oct 10/11/12, c. 1970 Winterland, Lithograph poster, 90 x 57 cm, frame 107 x 72 cm
Est: $200 - $300
Rick Griffin Jimi Hendrix Experience Buddy Miles Express and Dino Valentini etc Oct 10/11/12, c. 1970 Winterland Lithograph poster Number 140 © 1968 Bill Graham - Tea Lautrec Litho
Lawsons
Sep. 22, 2023
Rick Griffin, "Human Be-In Pow-Wow" 1967, Poster.
Est: $300 - $500
Griffin, Rick (American 1944-1991) Original relief half-tone poster, designed by Griffin. Printed by Berkeley Bonaparte in 1967 in Berkeley, California. Promoted as a gathering of all San Francisco rock bands, Saturday, January 14 at Golden Gate Park. Size: 14" x 20" Condition: Overall is good. Slight toning around the edges. Poster was previously rolled.
Quinn's Auction Galleries
Jul. 13, 2023
Rick Griffin puffing Kief
Est: $200 - $300
Heading: (Posters - Counterculture) Author: Griffin, Rick Title: A Puff of Kief in the Morning Makes a Man as Strong as a Hundred Camels in the Courtyard Place Published: Berkeley, CA Publisher:Berkeley Bonaparte Date Published: 1967 Description: Offset-printed poster. 49.5x35 cm (19½x14½"). Second printing of this head shop poster, the first to be printed in color.
PBA Galleries Auctions & Appraisers
May. 04, 2023
Rick Griffin's "Mornin Papa" rock poster
Est: $200 - $300
Heading: Author: Griffin, Rick Title: [Mornin Papa] The Family Dog Avalon Ballroom Fri-Sat-Sun, October 27-28-29...Quicksilver Messenger Service...Sons of Champlain... Place Published: San Francisco Publisher:Family Dog Productions Date Published: 1967 Description: Offset-printed poster on uncoated stock. 50.8x36.2 cm (20x14¼”). First printing. Scarce first printing of this classic Rick Griffin poster. The cartoon work would lead to an invitation by Robert Crumb for Griffin to join the Zap comix group. The present copy does not have either scratch indicating a second or third printing. King, FD-89-OP-1
PBA Galleries Auctions & Appraisers
Mar. 11, 2023
RICHARD "RICK" GRIFFIN, QUICKSILVER MESSENGER SERVICE, "ETERNAL RESEVOIR", POSTER
Est: $190 - $250
Artist: Richard "Rick" Griffin, American (1944 - 1991) Title: Quicksilver Messenger Service, "Eternal Resevoir" Year: 1968 Medium: Poster Size: 29 x 20 in. (73.66 x 50.8 cm) Publisher: Family Dog Productions, San Francisco Description: This poster was created by American artist Rick Griffin for the band "Quicksilver Messenger Service".
RoGallery
Jan. 26, 2023
Rick Griffin's "Sunday Funnies" rock poster
Est: $300 - $500
Heading: Author: Griffin, Rick Title: The Family Dog Avalon Ballroom Fri-Sat-Sun, October 27-28-29...Quicksilver Messenger Service...Sons of Champlain... Place Published: San Francisco Publisher:Family Dog Productions Date Published: 1967 Description: Offset-printed poster on uncoated stock. 50.8x36.2 cm (20x14¼"). First printing. Scarce first printing of this classic Rick Griffin poster. The cartoon work would lead to an invitation by Robert Crumb for Griffin to join the Zap comix group.
PBA Galleries Auctions & Appraisers
Nov. 27, 2022
Rick Griffin - Honk
Est: $500 - $5,000
21.5" x 26"
California Auctioneers
Oct. 06, 2022
Rick Griffin Canablis poster
Est: $200 - $300
Heading: (Rock Posters) Author: Griffin, Rick Title: Canablis Place Published: London Publisher:Alcock and Dicks Date Published: 1976 Description: Color poster. 51.5x73 cm (20½x29"). No. 2962 of an unspecified limitation. Nice example of the European edition of this classic Griffin design.
PBA Galleries Auctions & Appraisers
Jun. 16, 2022
[HENDRIX, Jimi (1942-1970)]. – [GRIFFIN, Rick (1944-1991), ...
Est: $400 - $600
[HENDRIX, Jimi (1942-1970)]. – [GRIFFIN, Rick (1944-1991), illus.]. – Group of 4 Tickets for the Jimi Hendrix Experience at Fillmore and Winterland. San Francisco: 1-4 February 1968. Original concert tickets in pink, yellow, blue, and black as designed by Rick Griffin for the Jimi Hendrix Experience’s four-night run at the Fillmore and Winterland with John Mayall and the Bluesbreakers and Albert King. 4 ½ x 2 ½”. These shows were the first that the Jimi Hendrix Experience ever played for concert promoter Bill Graham. Provenance: The Bo Overlock Collection.
Potter & Potter Auctions Inc.
Mar. 12, 2022
Rick Griffin, Contact, Big Brother & the Holding Company Poster, 1967
Est: $200 - $400
Rick Griffin (1944 - 1991) Contact, Big Brother & the Holding Company, The Sir Douglas Quintet, and Charles Lloyd at Avalon Ballroom Poster, 1967 offset lithograph Published by Family Dog Posters FD #52-1
Santa Fe Art Auction
Oct. 21, 2021
3 Family Dog Rick Griffin Concert Postcards
Est: $50 - $100
Richard Alden (Rick) Griffin (American, 1944-1991). 3 Family Dog Presents promotional concert postcards. No. 58-1, Goldrush: Quicksilver Messenger Service with John Hammond and his Screamin' Nighthawks and Charles Lloyd, Avalon Ballroom San Francisco, April 21-22, 1967. No. D-12, Chuck Berry with The Sons of Champion, The Family Dog, Denver, November 17-18, 1967. No. 60-1, Motherload: Big Brother & The Holding Co. with Sir Douglas Quintet and The Orchestra, Avalon Ballroom, San Francisco, May 5-7. 1967. Each 7" x 5"
Willow Auction House
Aug. 26, 2021
3 Family Dog Rick Griffin Concert Postcards
Est: $50 - $100
Richard Alden (Rick) Griffin (American, 1944-1991). 3 Family Dog Presents promotional concert postcards. No. 58-1, Goldrush: Quicksilver Messenger Service with John Hammond and his Screamin' Nighthawks and Charles Lloyd, Avalon Ballroom San Francisco, April 21-22, 1967. No. D-12, Chuck Berry with The Sons of Champion, The Family Dog, Denver, November 17-18, 1967. No. 60-1, Motherload: Big Brother & The Holding Co. with Sir Douglas Quintet and The Orchestra, Avalon Ballroom, San Francisco, May 5-7. 1967. Each 7" x 5"
Willow Auction House
Jul. 22, 2021
Rick Griffin's copy of Szukalski's god Krak
Est: $5,000 - $8,000
Heading: (Szukalski, Stanislav - Sculpture) Author: Szukalski, Stanislav Title: Krak - plaster cast of the upper half of the larger sculpture Krak Carried Away Place Published: No place Publisher: Date Published: 1940 [but cast in late 1950's] Description: Painted plaster maquette by sculptor Stanislav Szukalski. 14.7x11.5x4.5 cm (5¾x4½x1¾") With Szukalski's signature on reverse with his stylized "SZ" dated 1940 with some runic inscriptions. This hand-painted plaster maquette was given by Szukalski to psychedelic poster artist Rick Griffin and predates the establishment of Archives Szukalski and their late 1980's/early 90's issue of Szukalski bronzes. The present maquette represents only the top part of the sculpture The later bronze of the full sculpture was produced in an edition of 12 at a price of $7,500. Repair work to plaster was done by Szukalski himself. "Following Szukalski's belief in one prototypical Civilization emanating to all corners of the world after the great Deluge, Krak – namer of Krakow – is the Egyptian sun god Ra in another personification." - Bronzes of Szukalski, p. 12. Richard Alden "Rick" Griffin (1944-1991) was an American artist and one of the leading designers of psychedelic posters in the 1960s. As a contributor to the underground comix movement, his work appeared regularly in Zap Comix. Provenance: from the collection of Griffin's friend, artist Jacaeber Kastor.
PBA Galleries Auctions & Appraisers
Jul. 20, 2021
Goldrush / Quicksilver Messenger ("Pot"). 1967.
Est: $1,200 - $1,500
ARTIST: RICK GRIFFIN (RICHARD ALDEN GRIFFIN, 1944-1991) SIZE: 14 x 20 in./35.6 x 50.6 cm PRINTER: DESCRIPTION: Griffin enlists the Native American from the Family Dog's logo to create a bold double-entendre: "gold" refers to a strain of marijuana called Acapulco Gold, while "rush" refers to the sensation of being high—and obviously, our smoking Indian is placed within a large pot. It's a classic example of Griffin's love of puns, as well as his passion for symmetrical compositions. (Modern; Music; Psychedelic Rock; American)
Poster Auctions International Inc
Jul. 20, 2021
The Doors ("Pay Attention"). 1967.
Est: $1,700 - $2,000
ARTIST: RICK GRIFFIN (RICHARD ALDEN GRIFFIN, 1944-1991) SIZE: 12 3/4 x 21 1/2 in./32.3 x 54.6 cm PRINTER: DESCRIPTION: In one of Griffin's most ambitious images, an alien figure emerges from his ship to offer a "pay attention" pill to the viewer. This is the rare pre-concert printing of the design, featuring the red upper left corner with the Family Dog logo etched in black. This poster also marked the last concert presented in Denver by Family Dog under the auspices of Chet Helms. (Modern; Music; Psychedelic Rock; American)
Poster Auctions International Inc
Jul. 17, 2021
Poster by Rick Griffin - Grateful Dead Sons of Champlin poster for the album Aoxomoxoa
Est: €220 - €500
Grateful Dead Sons of Champlin poster for the album Aoxomoxoa - 55,5x66,5, 1969 by Rick Griffin (1944-1991)
Van Sabben Poster Auctions
Dec. 17, 2020
RICK GRIFFIN
Est: €200 - €300
Manifesto “Joint Show, San Francisco 1967”. Seconda stampa. Cm 71 x 56
Ansuini 1860 Auctions
Nov. 14, 2020
Rick Griffin, Vintage Concert Poster
Est: $150 - $250
Rick Griffin (American, 1944-1991) and Ivan Straus (American, 20th century), "Fly the World's Greatest Great Organ of Aerial Flight - Jefferson Airplane - Matrix 3138 Fillmore - April 11th, 12th 13th - Minors Wellcome," 1967, vintage concert poster, distributed by Berkeley Bonaparte (Berkeley, CA), sheet (unframed): 13"h x19.25"w. Provenance: Estate of Frank J. Caufield (San Francisco, CA)
Clars Auctions
Oct. 11, 2020
Rick Griffin, Vintage Concert Poster
Est: $300 - $500
Rick Griffin (American, 1944-1991) & Ivan Straus (American, 20th century), "Fly the World's Greatest Great Organ of Aerial Flight - Jefferson Airplane - Matrix 3138 Fillmore - April 11th, 12th 13th - Minors Wellcome," 1967, vintage concert poster, distributed by Berkeley Bonaparte (Berkeley, CA), sheet (unframed): 13"h x19.25"w. Provenance: Estate of Frank J. Caufield (San Francisco, CA)
Clars Auctions