It may not be up to them, but actually required by the department. For example, in my Calc classes, the professors HAVE to to something with Mathematica. Why the math department decided on that, I have NO idea...
As for books, you can get them used, through amazon, share with a friend, borrow from someone who doesn't need it, etc. Unless of course, your school has a book made JUST for your school. And it's brand new. So your only choice is to buy the brand new textbook... yeah, my school did that... ******* greedy assholes.
I'm starting to think I should have just knocked out the basics at community college. Oh well.