Rare Book Monthly

Articles - May - 2005 Issue

Converting Old Prices To Current Value: Finally A Tool

Want to see what has really happened to the value of this book?  Read on.

Want to see what has really happened to the value of this book? Read on.


By Michael Stillman

Figuring out the value of a book is probably the most vexing issue facing booksellers and collectors alike. Not that there is any lack of data. Books have been auctioned in the open market for over three centuries. Knowledgeable booksellers have been placing prices on them for at least that long. There is an enormous wealth of information. The problem is that many of these valuations are old. How can we use this enormous body of pricing data when the ravages of inflation and changing taste have made them seemingly meaningless?

The answer is to convert these old prices into current values. We need a scale, something akin to what the Consumer Price Index does for a loaf of bread. Such a scale could translate the price a bookseller or auction placed on that book years ago into today's dollars. It would bring those old prices up to date. Now updated prices would not necessarily establish current value. Some books will have appreciated more than others in the intervening years. Nevertheless, it would tell you on average what that old price equals today. It will tell you the value that bookseller or auction placed on your book. In a world where accurate pricing information is very hard to find, this would be a major step.

At the AE, we have been compiling an enormous database (the AE Bibliographic Database) of priced records, primarily from auctions and top booksellers of many generations. Now approaching a million strong, and growing rapidly by the day, these records give us a unique window into book pricing over the past century. Now we have sorted and selected through these reams of data to generate a scale that reflects the yearly trends in book pricing. So far, the scale takes us back to 1914, but in time it will go even farther. Once the scale was created, it became possible to apply it back to each individual record to determine what that old price means in terms of today's dollars. "Book dollars," if you will, for this scale is based not on the price of bread but on the price of books. It is, so to speak, the Consumer Price Index of books.

As we noted, not all updated prices will reflect current values because of differing rates of appreciation. However, this brings us to a second, and maybe even more important use for these updated prices. The ability to convert old prices into current values will tell you how fast a book is appreciating relative to other books, which is just a polite way of saying whether it has been a good or a poor investment. Think about that. If a book sold for $100 fifty years ago, and sold for $200 yesterday, it's been a terrible investment. Most books have far more than doubled in fifty years. But, if that book sold for the equivalent of $100 in today's "book dollars" fifty years ago, and $200 today, that is a book which is appreciating at twice the normal rate. Converting old prices to current values enables you to see which books are good investments, which are not so good. Now, if your interest in books is strictly for the pleasure they bring you, then you need read no further. If at least part of your motivation in buying books revolves around money, then please continue.

Rare Book Monthly

  • Forum Auctions
    Natural History: The remaining stock of Antiquariaat Junk, 1899-2026
    25 March 2026
    Forum, Mar. 25: Botany.- Andrews (H.C.) Coloured Engravings of Heaths, 4 vol. in 2, first edition, [1710,--94]-1802-1809-[1830]. £10,000 - £15,000.
    Forum, Mar. 25: Butterflies.- Cramer (Pierre) and Caspar Stoll. De Uitlandsche Kapellen voorkomende in de drie Waereld-Deelen…,, 5 vol., Amsterdam & Utrecht, 1779-91. £8,000 - £12,000.
    Forum, Mar. 25: Voyages.- Darwin (Charles) and others. Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle, 3 vol. in 4, including Appendix to vol.2, first edition, 1839. £8,000 - £12,000.
    Forum, Mar. 25: Butterflies.- de Graaf (Willem Diederik Vincent). [Inlandsche Kapellen in beeld], 170 fine original watercolours, [Enkhuizen], [1800-40]. £8,000 - £12,000.
    Forum Auctions
    Natural History: The remaining stock of Antiquariaat Junk, 1899-2026
    25 March 2026
    Forum, Mar. 25: Birds.- Dresser (Henry Eeles). A History of the Birds of Europe, 9 vol., including supplement, first edition, by the author, 1871-96. £6,000 - £8,000.
    Forum, Mar. 25: Zoology.- Felines.- Elliot (Daniel Giraud). A Monograph of the Felidæ or Family of the Cats, first edition, for the Subscribers, by the Author, [1878]-1883. £25,000 - £30,000.
    Forum, Mar. 25: Birds.- Frisch (Johann Leonard). Vorstellung der Vögel Deutschlandes, 2 vol., first edition, Berlin, Friedr. Wilhelm Birnsteil, [1736]-1763. £40,000 - £60,000.
    Forum, Mar. 25: Birds.- Gould (John). The Birds of Great Britain, 5 vol., first edition, by the author, 1862-1873. £30,000 - £40,000.
    Forum Auctions
    Natural History: The remaining stock of Antiquariaat Junk, 1899-2026
    25 March 2026
    Forum, Mar. 25: Pomology.- France.- Poiteau (A.) Pomologie Française. Recueil des Plus Beaux Fruits cultivés en France, 4 vol., Paris, 1846. £30,000 - £40,000.
    Forum, Mar. 25: Botany.- [Robin (Jean)]. Histoire des Plantes, nouvellement trouvées en l'Isle Virgine…,, 1620; with Geoffrey Linocier L'Histoire des plantes, second edition, 1619-20. £3,000 - £4,000.
    Forum, Mar. 25: Asia.- Japan.- Siebold (P.F. von). Nippon. Archiv zur Beschreibung von Japan, 7 parts in 6 vol., first edition, Leyden, [1832]-1852. £35,000 - £45,000.
    Forum, Mar. 25: Asia.- Valentijn (Francois). Oud en Nieuw Oost-Indiën..., 5 vol. in 8, first edition, Dordrecht [&] Amsterdam, 1724-26. £8,000 - £12,000.
    Forum, Mar. 25: Botany.- Australia.- Redouté (P.J.).- Ventenat (Étienne Pierre). Jardin de la Malmaison, 2 vol.,, Paris, 1803-04[-05]. £30,000 - £40,000.
  • ALDE, Mar. 11: AUGUSTIN (Saint). De civitate Dei. Rome, Konrad Sweynheym et Arnold Pannartz, 1470. €20,000 - €30,000.
    ALDE, Mar. 11: [REGNART (LE LIVRE DE)]. [Le] Docteur en malice, maistre Regnard, demonstrant les ruzes et cautelles qu'il use envers les personnes… Rouen, 1550. €20,000 - €30,000.
    ALDE, Mar. 11: TRITHÈME (JEAN). Polygraphie et universelle escriture cabalistique. Paris, [Benoît Prévost pour] Jacques Kerver, 1561. €8,000 - €10,000.
    ALDE, Mar. 11: CAUS (SALOMON DE). La Perspective, avec la raison des ombres et des miroirs. Londres, John Norton, 1612.
    ALDE, Mar. 11: NICERON (JEAN-FRANÇOIS). La Perspective curieuse ou magie artificielle des effets merveilleux de l'optique. Paris, Pierre Billaine, 1638. €6,000 - €8,000.
    ALDE, Mar. 11: VONTET (JACQUES). L’Art de trancher la viande et toute sorte de fruits… S.l.n.d. [probablement Lyon, vers 1647]. €20,000 - €30,000.
    ALDE, Mar. 11: HUGO (VICTOR). [Paysage spectral avec une église], [vers 1837]. €20,000 - €30,000.
    ALDE, Mar. 11: [HERVEY DE SAINT-DENYS (LÉON D')]. Les Rêves et les Moyens de les diriger. Observations pratiques. Paris, Amyot, 1867. €3,000 - €4,000.
    ALDE, Mar. 11: GACHET (PAUL-FERDINAND). Les Chats de Gachet (Manuscrit). S.d. [avant mai 1873]. €6,000 - €8,000.
    ALDE, Mar. 11: [REDON (ODILON)]. PICARD (EDMOND). Le Juré. Monodrame en cinq actes… Bruxelles, Mme veuve Monnom, 1887. €7,000 - €9,000.
    ALDE, Mar. 11: [TOULOUSE-LAUTREC (HENRI DE) ET HENRI-GABRIEL IBELS]. MONTORGUEIL (GEORGES). Le Café-concert. Paris, [1893]. €4,000 - €5,000.
    ALDE, Mar. 11: [TERRY (EMILIO)]. Projet de fontaine. Dessin original au stylo et à l'encre noire. 1938. €2,000 - €3,000.
  • Chiswick Auctions
    Books & Works on Paper
    12th March 2026
    Chiswick, Mar. 12: Churchill: The World in Crisis. Inscribed in 4 vols. 1923-31. £18,000 - £22,000.
    Chiswick, Mar. 12: Rowling. Harry Potter and the Philosopher's Stone. Inscribed. £6,000 to £8,000.
    Chiswick, Mar. 12: Ponting. Polar Photographs (2) 1910-11. £3,000 - £4,000.
    Chiswick, Mar. 12: Gray [Artist.] India. Album 40 original drawings. 1858 - 1862. £2,000 - £3,000.
    Chiswick, Mar. 12: Lane’s Celestial Globe, 1811. £600 - £800.

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