The worth of used textbooks depends on how much they sell for on the open market, their edition and condition. Common buyback sites include Amazon.com, Half.com, TextbookX.com and Textbooks.com. These sites are alternatives to selling back textbooks to a college bookstore.
Sites such as Chegg.com compare their buyback price to a list of prices from other sites, making it easier to choose an online retailer. BigWords.com offers a price comparison of buyback sites to sell to.
To keep textbooks intact to get the most money when selling them, seal the edges of the book with painter's tape and use sticky notes and document flags instead of highlighting and writing in the books.