The value of a book is dependent upon many variables. For example, considerations include whether it is a first edition, if it is inscribed, or if it has a dust jacket. The condition of the dust jacket and the book also affect the book's value. This is only a short list of considerations.
There are some bookstores that specialize in Sinclair Lewis materials including :
Robert Dagg Rare Books
3288 21st St., #176
San Francisco, CA 94110
Joseph the Provider Books Bought & Sold
P.O. Box 90
Santa Barbara, CA 93102
Ralph Sipper Books Bought & Sold
10 West Micheltorena St.
Santa Barbara, CA 93101
Please visit our links page to see more collectors of Sinclair Lewis.