Where can I sell my college paper textbook?

I paid $150 for a Marketing book. It doesn't have a spine or hard cover. It's all pages with holes punched in them. I bought it new. Now the bookstore won't buy it back because it's a paper textbook. Is there any other places that would buy it?Where can I sell my college paper textbook?
Amazon or Ebay are common solutions. Online textbook exchanges are other possibilities. Moreover, their are often student run textbook exchanges on larger campuses. Where can I sell my college paper textbook?
The best place to sell your textbook will be at the prof's next class. Go the first day and try and sell it to one of the students there for, say $100 or even $125. They'll save money and you'll make some back. If your prof isn't teaching the same class again, you're really out of luck, unless you go to the prof's office hours and ask/demand why a spiral bound reader costs so much and try and sell it back to him/her!