I'm not sure if my professor was being nice or not as savvy as you describe because the course was taught with a printed out book by him and another professor but all he charged for the entire book (plus homework problems) was 40 bucks USD. This was back in 2006 so I don't know what he's charging now (assuming he's not retired by now). By comparison, the average new book at the university book store was around 80 USD (at the lowest).