I'm very happy I went to a University that had text book rental. When I was in school it was $7 per credit. So taking a full 16 credit load would cost $112 per semester for text books. Regardless of if the course used one, ten, or no books the fee was included. So I paid $7 for text book rental for water polo (1 credit "class" with no books), $21 for an upper level CS course with perhaps 1 book, and $21 for an English class that may have required reading 10 books. We never had to deal with selling the books back since we never bought or owned the books. If after a course, particularly a course in your major, if you wished to keep the book you could by paying for it.

EDIT: I have heard that most people would spend $112 on a single course, let alone even a single book. I don't think the publishers and text book companies really like(d) my University. Yes, this is in the U.S. too. I think if a school's student body comes together and "demands" text book rental they can get it. Talk to your student council and apply pressure on the staff and faculty to incorporate it.