I recently came across a website that lets you rent your textbooks for a semester (or quarter or summer). It’s called Chegg and you actually rent the book and send it back after you’re done. They boast that you can save up to 80% and help the environment. For every textbook that you rent from Chegg, they will plant a tree.
I tried it out and got an art book for the fall semester for only $50. Used ones even from Amazon were quoted at over $90. Chegg sometimes orders the books from resellers (such as Amazon) and has them sent directly to you (in the case that they didn’t have any on hand). You can do some light highlighting, but no writing in the books. It’s a pretty good service and I’m happy with it so far. The book arrived about four business days after I placed the order.