Old books, like old money, need to be translated into today's values
Today there are numerous ways to know what the asking prices of books are and as Mike Stillman has correctly pointed out these are the prices of all the books that have not sold. What we show you are almost a million records of books, manuscripts and ephemera that have sold and we adjust the prices to current value. Now, for the first time, you can obtain a reasonably good idea of what your book is worth using a systematic process that identifies appropriate records, adjusts them to current value and averages them to provide you with a single valuation. Stray and inconsistent records are easily checked and eliminated if inappropriate.
Ultimately a seller may not agree to sell at the historically derived value but there is simply no reason not to know what the market history is. If you don't want to know it before you buy you will in any event learn all about it when you decide to sell. It's called reality. You may well have to pay more to buy material than these projected valuations suggest but you will also feel empowered to buy when the offers are well below what history suggests the real value is. Most booksellers want to sell their books. Some become argumentative if you discuss price but most will listen to an offer. If, in a reasonable amount of time, they believe they'll sell their book for their price they aren't going to discuss any concessions. If not, they will prefer to negotiate rather than lose the chance to sell their book to a knowledgeable buyer. This software helps both buyers and sellers to find the middle ground.
The development of this project has been undertaken by Mike Stillman, evaluated by Jenny McKinney who has already proposed a second version we'll begin work on this summer and implemented by Wei-cheng Chu, our software engineer. It is an important step in the evolution of bookselling on the net.
If you would like to sign up for a week or a month to give this software a work out click here and we'll take you to the sign-up page. A one week sign up is $7.95, a month $14.75, a year $141.60. For years the book business has been all about "asking prices." This is a step toward building the "bid side."
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 156: Cornelis de Jode, Americae pars Borealis, double-page engraved map of North America, Antwerp, 1593.
Swann, Dec. 9: Lot 206: John and Alexander Walker, Map of the United States, London and Liverpool, 1827.
Swann, Dec. 9: Lot 223: Abraham Ortelius, Typus Orbis Terrarum, hand-colored double-page engraved world map, Antwerp, 1575.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 233: Aaron Arrowsmith, Chart of the World, oversize engraved map on 8 sheets, London, 1790 (circa 1800).
Swann, Dec. 9: Lot 239: Fielding Lucas, A General Atlas, 81 engraved maps and diagrams, Baltimore, 1823.
Swann, Dec. 9: Lot 240: Anthony Finley, A New American Atlas, 15 maps engraved by james hamilton young on 14 double-page sheets, Philadelphia, 1826.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 263: John Bachmann, Panorama of the Seat of War, portfolio of 4 double-page chromolithographed panoramic maps, New York, 1861.
Swann, Dec. 9: Lot 265: Sebastian Münster, Cosmographei, Basel: Sebastian Henricpetri, 1558.
Swann, Dec. 9: Lot 271: Abraham Ortelius, Epitome Theatri Orteliani, Antwerp: Johann Baptist Vrients, 1601.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 283: Joris van Spilbergen, Speculum Orientalis Occidentalisque Indiae, Leiden: Nicolaus van Geelkercken for Jodocus Hondius, 1619.
Swann, Dec. 9: Lot 285: Levinus Hulsius, Achtzehender Theil der Newen Welt, 14 engraved folding maps, Frankfurt: Johann Frederick Weiss, 1623.
Swann, Dec. 9: Lot 341: John James Audubon, Carolina Parrot, Plate 26, London, 1827.
Sotheby’s Book Week December 9-17, 2025
Sotheby’s, Dec. 11: Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] Journal of the Proceedings of the Linnean Society, Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.
Sotheby’s, Dec. 11: J.K. Rowling. Harry Potter and the Philosopher's Stone, 1997, first edition, hardback issue, inscribed by the author pre-publication. £100,000 to £150,000.
Sotheby’s, Dec. 11: Wolfgang Amadeus Mozart. Autograph sketchleaf including a probable draft for the E flat Piano Quartet, K.493, 1786. £150,000 to £200,000.
Sotheby’s, Dec. 12: Hooke, Robert. Micrographia: or some Physiological Descriptions of Minute Bodies made by Magnifying Glasses. London: James Allestry for the Royal Society, 1667. $12,000 to $15,000.
Sotheby’s, Dec. 12: Chappuzeau, Samuel. The history of jewels, first edition in English. London: T.N. for Hobart Kemp, 1671. $12,000 to $18,000.
Sotheby’s, Dec. 12: Sowerby, James. Exotic Mineralogy, containing his most realistic mineral depictions, London: Benjamin Meredith, 1811, Arding and Merrett, 1817. $5,000 to $7,000.
![<b>Sotheby’s, Dec. 11:</b> Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] <i>Journal of the Proceedings of the Linnean Society,</i> Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.](https://ae-files.s3.amazonaws.com/AdvertisementPhotos/00d5fd41-2542-4a80-b119-4886d4b9925f.png "<b>Sotheby’s, Dec. 11:</b> Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] <i>Journal of the Proceedings of the Linnean Society,</i> Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.")
