The instructors I had were notorious to pirate as well. They'd sell photo copied bundled "text books" from other textbooks as the required edition so they get part of the profit from the sale of the book and maybe include some pirated copy of a movie or some other materials they stole online.
When I studied in South America, our professors were very open about it. None of us could have afforded textbooks anyway (by a large margin), so usually, only the professors would have the original textbook and worked with the small photocopy business located on campus to scan the book once and print as many copies as the students needed. The copies were bundled properly and all. Same with any software, files or operating system.
Eh. I'm sure there's some of that going on, but if you're buying a course pack through the university book store, there's a pretty good chance you're just paying printing (it hard copy) and licensing fees.
A lot of university textbook publishers will sell the content of the books per chapter to university book stores.