Book collecting began long before the existence of books as we know them today. Street vendors sold best-selling books (scrolls) in ancient Rome and many wealthy Romans boasted of their book collections. Recently a large private library of ancient scrolls was uncovered near Pompeii. Book collecting resumed in the Renaissance shortly after the invention of movable type. It continues to be a passion of millions of people.
Collecting can be done on any budget. Most often it is the result of a collector's passion for an area of interest, and is done for pleasure and knowledge, not necessarily for profit.
Some of the major areas of collecting include cookbooks, children's books, award-winners, first books of authors, works of a specific writer or illustrator, and subject or genre areas such as history, science, nature, travel, sports, hobbies, art and antiques, science fiction, fantasy, horror, mystery, modern literature, vintage paperbacks, and many others. Books of certain publishers are collected, including the Limited Editions Club, Heritage Press, Easton Press, Modern Library, Everyman's Library, and many small specialty presses.
The value of a collection may be secondary to many collectors, but for others it is quite important. Sometimes just the completeness of a collection will give it value, particularly if such collections are quite uncommon. In general, however, there are fairly standard methods used in valuing books.
The most important determinants of the value of a book are condition, edition, scarcity, and demand.
Condition is to value in books what location is to value in real estate. Collectors are very concerned about condition and usually will not buy books that do not meet their condition requirements. The closer a book is to as-new condition, the greater its value will be. And that applies to all books, regardless of age. In fact, age has almost nothing to do with the value of books, except for books that are very old, i.e. from the 15th, 16th and 17th Centuries.
Condition is critical for both the book and the dust jacket. Dust jackets represent 75-90% of the value of most collected works of fiction. Thus, a copy of the first edition of The Great Gatsby, with a dust jacket, today is worth $50,000-$150,000 depending on condition. The same book, without a dust jacket, is $1500-7500. Writings in books, except those by famous people, are serious flaws. Ex-library copies, particularly of fiction, should be avoided.
Collecting first editions requires some knowledge of how editions are identified, and particularly with older books identifying a first edition can be complicated. First printings, or "first states" of first editions almost always are far more valuable than any other printings of that book by that publisher. With older books there can be subtle differences between printings resulting in huge differences in values. There are many reference works that serious book dealers use to properly identify their books. Good starting point references are The Pocket guide to the Identification of First Editions, published by McBride, John Carter's ABC for Book Collectors, and Book Collecting 2000, as well as Collected Books (1998) both by Allen and Patricia Ahearn.
In general, book club editions have little or no value, except where the book club is the only hardcover edition. It sometimes is difficult to tell a book club edition from a first edition because the same plates may have been used for both. Most book club editions will not have a price on the front flap of the dust jacket. For this reason, if a dust jacket has been price clipped it will be considered seriously flawed, and its value will be less. For many years a small dot, or square, impression was stamped in the lower right corner of the rear board, signifying a book club edition, but that practice seems to have stopped.
Most books are easier to collect today than ever before because the Internet has opened up a world market. At the same time collecting the truly rare books is becoming more and more expensive. The Internet has made it possible to see how scarce a book really is. The result is that the truly scarce books that still are in demand are escalating rapidly in value. Books that are available in large numbers are decreasing in value. The unfortunate aspect of today's Internet bookselling is that there are many people selling books who are not professional book dealers, know little about what they are selling, and sometimes provide very unreliable service. Most professional dealers provide a reasonably proper bibliographic and condition description of their books. If all a seller says in a listing is that they have sold thousands of books, or has some other self-promoting statement, without telling you anything about that book, then beware, and look elsewhere.