I used to be an English teacher at what Penthouse forum would call "a major mid-Atlantic university." One of the things about teaching English is that it's impossible to escape the high cost of books. Unlike PE teachers, art professors, or the guys who teach underwater basket weaving, English instructors have to assign texts, which means that our students end up having to lay out a lot of dough.
I fought against this by carefully choosing my books. Whenever I assigned a text, I would look at all the available editions and consider the benefits versus the costs of each one. I often used xeroxed copies of stories or placed reserve copies in the library to reduce my students' textbook burden, and prided myself on the relatively cheap cost of supplies for my classes.
One year, attempting to standardize its introductory classes, my department developed an in-house textbook. Initially, using the book was a voluntary choice, but over the years, the department textbook became required for every freshman English class. For a while, this wasn't too much of a problem; the textbook was pretty decent, and I can honestly say that it helped my students. In my final year, however, the department came out with a completely worthless edition of the damned thing. It cost $90, and I was required to assign it in my classes. In my last semester, I decided against using it, which earned me some stink-eye from a few colleagues, but little else. On the other hand, I had already announced my decision to leave teaching.