Determining the value of a book can be a very intricate process. Professional booksellers take many things into consideration when determining a fair market value of a title. Condition, edition, scarcity, demand, and age are all factors.
You can get the basics of searching and finding the value of your books here:
If you feel you may have a book that is worth a considerable sum, we highly recommend that you find a seller of rare books in your area who performs professional appraisals. There may be a cost involved, but having a professional bookseller evaluate your book before you attempt to sell will ensure that you ask for a fair price. If you intend to keep the title, appraisals can also assist you in properly insuring your property against future damage or loss.
To find a Biblio bookseller in your area that may offer appraisal services or be interested in purchasing your items, you can go to the following page and narrow your search to state or province: