Be careful if you opt for international versions. They're NOT always as "exactly the same" as they claim to be. I've seen a couple that had questions/quizzes on different pages, or had different questions/quizzes, some were in metric instead of standard US measurements, stuff like that. Sure, you MAY get a refund...but it'll take time.
When I had books I didn't want to keep, I sold them to other students at a tremendous discount. Saved them a lot of money, made a bit for me.