We had a table of textbooks at our garage sale last month, each priced $1.00--we just wanted to get rid of them. A customer at my garage sale told me we should try to sell them online. Since we had our laptops in the garage, to surf during the lulls, my husband did some searching.
He was able to sell nearly all 25 of the books for a grand total of $338.00, much better than my $1.00 per book price.
He sold to three places: Barnes & Noble, Ecampus books, & I can't remember the third one. He told all of his class mates to type in the ISBN number into a word document. Then you could go to the different sites, [and there are many more] and cut and paste the ISBN numbers.
Each of the companies provided prepaid mailers, and we boxed all of the books up and sent them away. We received payment from all three companies. We were mostly looking to get rid of books NO one in our house will ever read.
My advise...keep checking sites. We did have a couple of "losers" those we donated to our local goodwill our library does not take textbooks. They will sell if for a $1.59.