If only I had thought of this while in school, I could have been a millionaire by 25 years old. Every American who has gone to an institute of higher education knows the cost of textbooks.
It is not uncommon for one textbook to cost $50 to $150 and most courses require multiple books. When I taught in CA, I would try to choose the required texts bearing in mind the cost of the books, knowing the financial pressures of being a student. It was not always possible. When students sell their books back at the end of the semester, they only get nickels on the dollar. This is a fantastic alternative. It still seems pricey to me, but then again, in comparison with new books, there is some savings.
Rent your college texts from Book Renter for 30 day increments or a semester. For example, the book I will be using in the fall semester for a new Masters class is called Social Problems. To purchase the book new is $118.40. However, a rental is $46.16 for a full semester. Not sure if you want to stay in the class? Then rent it for 30 days for $33.47.