I've been looking up cheap ways to get required textbooks for my classes. But some of these classes have an online homework/assignment system which can only be accessed via a unique code (so used books are out of the question since their code has already been used. Textbooksrus has some cheap versions but don't mention having the code). So I'm sorta being forced here to buy the whole (new) book just to get access to homework. What do you suggest I do?
Example:
Chemistry: The Molecular Science, 5th, Loose-Leaf + [homework] OWLv2 24-Months Instant Access