It took me a couple of classes of barely or never using books to start doing #1 in conjunction with the library/sharing of #2. It also helps if you can get an idea of the books in advance from someone who just took the course, giving you a chance to grab a library copy before they are all checked out.

In my experience I did get a couple of professors that weren't pleased when I didn't get the book(s).

One frustrating thing was professors assigning their own books. There were a couple of cases where much of the class was directly related to it, but otherwise it was for vanity/$$$.