Note: the price guide at the foot of this article and the comments below have been reviewed and updated as of August 2023. There will be additional updates after the next significant auction which will be at the end of September 2023 when Christie's auction of the Charlie Watts collection is complete.
The first step in determining the value of a book is to confirm it is actually a first edition - whether a global first or a national first. For insights on identifying firsts, please see our series of articles on this topic (search "Collecting Christie True Firsts").
The value of an Agatha Christie first edition is heavily influenced by condition. The difference between a near fine dust jacket and a good only jacket is vast. This is exponentially true for books published in the 1930s and earlier. In general the best indication of value is to examine recent auction results. For books from the 1950s and later, eBay is the best resource for prices realised and their database is easily searchable. Larger auction firms still generally group books together from these later decades. However, pay particular attention to the visuals, not just the text. eBay is rife with inaccurate descriptions - both in grading and actual book points. For books from the 1920s-1940s, auctions are the best indicators of true market value.
Recent significant auctions of Agatha Christie have been as follows:
5-September-2019 at Heritage Auctions in the USA (exchange rate: 1.22)
4-February-2021 at Sotheby's in the UK (exhange rate: 1.37)
28-July-2022 at Heritage Autions in the USA (exchange rate: 1.20)
All prices realized (listed below) include the buyer's premium (but do not reflect VAT/sales taxes which depend on residency). The exchange rate provided is US dollars per UK pound, so adjust accordingly to convert to your currency of choice at that time.
Generally, domestic books sell better at domestic auctions (i.e. UK books at a UK auction). Buying across markets - a UK book at a US auction or vice-versa - generally offers better value for money. This may be the shipping and customs hassle effect. Most collectors of US books are in the US, so buying in the UK poses more logistical challenges.
Signatures: Valuations will increase significantly when signed or inscribed. An authentic signature will generally add £500-1,000 in value. An inscribed copy to a close connection of Christie's will command more, but value will be determined through the eyes of the buyer. Before buying any signed item, please read our article on 'Fake or Fortune' (link).
Condition: Generally, all books and dust wrappers from the Heritage Auction were in 'near fine' condition, though a few had some restoration or chipping. The Sotheby's auction had significant variance in jacket quality. For full details on that auction click here. Books or jackets / wrappers of poorer quality certainly detract heavily and thus significant price reductions should be expected. Books not listed were not at either auction as there were no reserve items, or were sold in multi-book lots (so hard to confirm individual value) or realized values under $500.
Prices References:
HA19: Heritage auction on 9/2019. Books and jackets were generally above average.
SB21: Sotheby's auction on 2/2021. Books and jackets were generally above average.
HA22: Heritage auction on 7/2022. Books and jackets were generally of a slightly lower quality than HA19.
Notations: Prices reflect a 'very good' jacketed copy with no major flaws unless noted. Common observations are abbreviated with one of the following notations:
(bk): Book only, no jacket.
(F-dj): Fine dust jacket - one that is exceptional for its age and most uncommon.
(G-dj): Good-only dust jacket, thus with numerous flaws, damage or missing pieces.
(L-dj): Later state dust jacket. If the version is none, it will be noted.
(s): Signed only, or signed to an unknown person.
(i): Inscribed - i.e. signed to a known person or with unique comments.
UK FIRSTS in jackets unless noted
1921 The Mysterious Affair At Styles: HA19 $10,625 (bk); SB21 £4,032 (bk)
1922 The Secret Adversary: HA19 $3,250 (bk); SB21 £1,008 (bk)
1923 The Murder on the Links: SB21 £7,560 (bk)
1924 Poirot Investigates: HA19 $2,500 (bk); SB21 £1,260 (bk)
1924 (27) Poirot Investigates (first 'cheap edtn' 3/6 jacket): HA19 $6,250
1924 The Man In The Brown Suit: HA19 $1,250 (bk); SB21 £1,512 (bk)
1925 The Secret of Chimneys: HA19 $1,375 (bk); SB21 £1,512 (bk); HA22 $812 (bk)
1926 The Murder of Roger Ackroyd: HA19 $1,031 (bk); SB21 £2,772 (bk); HA22 $850 (bk)
1927 The Big Four: HA19 $600 (bk)
1928 Mystery of the Blue Train: HA19 $22,500
1930 The Mysterious Mr. Quin: HA19 $18,750; SB21 £20,160
1930 Murder At The Vicarage: HA19 $575 (bk)
1931 The Sittaford Mystery: HA19 $1,625 (bk)
1932 Peril at End House: SB21 £6,930
1933 Lord Edgware Dies: SB21 £27,720
1933 The Hound of Death (Odhams): HA22 $1,000
1934 Murder on the Orient Express: HA19 $3,875 (bk); SB21 £13,860
1934 Why Didn't They Ask Evans: HA19 $22,500; SB21 £6,048
1935 Three Act Tragedy: SB21 £3,276 (L-dj)
1935 Death in the Clouds: SB21 £2,016 (G-dj)
1936 The ABC Murders: SB21 £47,880 (F-dj)
1936 Cards on the Table: SB21 £2,772
1936 Murder in Mesopotamia: SB21 £4,788
1937 Dumb Witness: HA19 $15,625
1937 Murder in the Mews: SB21 £30,240
1937 Death on the Nile: SB21 £5,670
1938 Appointment With Death: HA19 $9,375; SB21 £3,276
1938 Hercule Poirot's Christmas: HA19 $3,250; SB21 £2,106
1939 Ten Little Niggers: HA19 $4,500; SB21 £3,024
1939 Murder is Easy: SB21 £1,638
1940 One, Two, Buckle My Shoe: HA19 $2,375; SB21 £882
1940 Sad Cypress: HA19 $3,250; SB21 £1,386; HA22 $4,250
1941 Evil Under the Sun: SB21 £1,638; HA22 $1,250
1941 N or M: HA19 $1,000; HA22 $1,125
1942 The Body In The Library: HA19 $1,187; SB21 £1,764
1943 The Moving Finger: HA19 $1,000
1944 Towards Zero: HA19 $700
1945 Sparking Cyanide: HA19 $500
USA First Editions in jackets:
1920 The Mysterious Affair At Styles: HA19 $10,625 (bk)
1923 Murder on the Links: HA19 $17,500; HA22 $2,000 (bk)
1925 Poirot Investigates: HA19 $13,125
1926 The Murder of Roger Ackroyd: HA19 $4,125
1927 The Big Four: HA19 $4,750
1927 Partners in Crime: HA19 $2,750; SB21 £1,071
1928 The Mystery of the Blue Train: HA19 $2,000; HA22 $1,312
1929 The Seven Dials Mystery: HA19 $2,625; SB21 £819
1930 The Murder At the Vicarage: HA19 $3,250; HA22 $937
1930 Mysterious Mr. Quin: HA19 $1,875; HA22 $1,652
1931 Murder At Hazelmoor: HA19 $1,875; SB21 £567; HA22 $906
1932 Peril At End House: HA19 $2,000; SB21 £1,638; HA22 $1,875
1933 Thirteen At Dinner: HA19 $1,500
1933 The Tuesday Club Murders: HA19 $5,500
1934 Parker Pyne Detective: HA19 $3,000; HA22 $687
1934 Murder in the Calais Coach: HA19 $6,250
1934 Murder in Three Acts: HA19 $2,750; SB 21£693; HA22 $687
1935 The Boomerang Clue: HA19 $1,187
1935 Death in the Air: HA19 $2,750
1936 The ABC Murders: HA19 $2,000 (incl both 1st state jackets)
1936 Murder in Mesopotamia: HA19 $1,562; SB21 £2,268; HA22 $1,812
1937 Dead Man's Mirror: HA19 $2,000
1937 Poirot Loses A Client: HA19 $937
1937 Cards on the Table: HA19 $1,625
1938 Death on the Nile: HA19 $4,000; HA22 $1,125
1938 Appointment With Death: HA19 $875
1939 Easy To Kill: HA19 $1,125
1939 The Regatta Mystery: HA19 $2,625; HA22 $2,000
1939 Murder for Christmas: HA19 $1,625
1940 And Then There Were None: HA19 $3,500; SB21 £504
1940 Sad Cypress: HA19 $900
1941 Evil Under The Sun: HA19 $3,250; HA22 $1,375
1941 The Patriotic Murders: HA19 $700
1942 Murder in Retrospect: HA19 $700
1942 The Moving Finger: HA19 $875
1942 The Body In The Library: HA19 $1,687
1948 Witness for the Prosecution: HA19 $1,375; SB21 £945