[censored],
This may help you in your search for books on the cheap:
http://www.bookmooch.com/
You put up a list of books you're willing to part with, and if anyone asks for one you ship and pay, and you can also ask other people for their books, and they will ship and pay.
I haven't tried it, but Clark Boyd (the former host of The
World's Tech Podcast) claims he got free MIT text books through it. Apparently the selection is wide.