About books...I figured it was worth it to drop the extra couple hundred bucks and buy new copies of the latest edition. A lot of times in class a professor or another student might reference a page number and you might want to look it up, especially if it's while the professor is calling on you. Plus the effort of going to lexis,etc if cases are missing from your edition wouldn't be worth it for me, especially since you're getting the whole case on lexis, which will probably include lots of stuff irrelevant to that class, instead of the edited casebook version.
But I know some people who bought old versions. I'm sure it worked out fine for them.