Agreed, this has been done many times but it never stuck. I started this website a few years ago while in college and faced similar challenges. As someone ment

Agreed, this has been done many times but it never stuck. I started this website a few years ago while in college and faced similar challenges. As someone mentioned in another comment "chicken and egg problem to the extreme." In my experience, students already reach out to their friends/classmates to solicite cheaper textbook pricing, a website would be a good medium to facilitate this and helps avoid the many listserv emails asking for books. One thing I've tried my best to do is to lower the barrier to post a book for sale and communicate with sellers: there are no sign ups required and I've opted for non-captcha spam validation (for now) -- this is to help with the adoption. Edit: spelling