I am desperately trying to find books the cheapest way possible. But I need help. How important is the copyright date of a textbook? My school requires certain editions...but the copyright dates are so new...like 2011 and 2012. I feel like I am up to my eyeballs searching b/c I am finding the right editions but the copyright is off by year or even 6months! The other that is so frustrating is finding cd and study guides to match! Help....