Some Terms and Attributes to Consider when Buying Old Books

"Points"--Modern editions (post-1800) are especially volatile in price because there are so many copies of a given edition available and so many editions of successful works were printed.  Individual typographic differences ("points") among editions can determine whether a copy is a "first edition," a "first printing of the first edition," or even "a first state of the first printing of the first edition."  The "firsts" were all the books made with a given setting of type, including stop-press corrections.  "First printings" may differ from mere "firsts" because when the printer decided demand was strong enough to reprint without entirely resetting the type, points of difference can emerge between a first or second printing (e.g., a publisher might add a "blurb" announcement to the title page or dust jacket).  Points identifying early hand-press editions also exist, but copies from individual printings often differ in many "points" from other legitimate copies due to more frequent stop-press corrections.

"Condition"--Is the binding fresh and "as issued," or faded, spotted, sun-faded, etc.?  Is the interior of the book marked by former owners, which almost always reduces asking prices except when the former owners were famous and/or relevant to the author (e.g., Boccaccio's annotated manuscript copy of Virgil)?  If the book was issued with a publisher's binding (post-1825-30) or dust jacket, is the binding or dust jacket present and in what condition?  Have the interior pages been browned by sun-exposure ("foxed"), creased, torn (especially "with loss of text"), or otherwise damaged?  Is the entire text-block still squarely in line with the binding, or has it sagged down toward the fore-edge ("cocked") from long vertical storage on a bookshelf?  In older hand-press books, have bookworms attacked any pages and for how many pages does the damage run (also, "with loss of text"?)?

"Association copies"--books owned by or inscribed by the author, friends of the author, other authors, or famous persons, tend to command higher prices than unmarked books.  Old books which were heavily annotated by intelligent readers from previous eras of history can be considered more valuable if they shed light on previous readers' interpretations of the text.

Some general rules: book prices tend to rise over centuries, but they also can fall if the collector marketplace is struck by war or economic panics.  Individual authors or types of books can attract astonishingly inflated prices based solely upon an elite market demand (e.g., the rage for Caxtons since about 1750, the pursuit of incunables since the 1600s, the market for individual press's output like the Aldines or Elziveres).  Book buyers may be mad, greedy speculators, passionate fans, or just curious civilians, but all of their appetites may be appealed to by booksellers' descriptions, which range from the "scientific" (just the points and condition) to the "poetic" (rhapsodies about the book's or author's importance to culture, etc.).  Beware the latter!