Remember Amazon used isn't really Amazon, just some random person. $30 is terrible IMO since it's close to that new (or was anyway).
Awesome game IMO if you like the concept (Bioware real science-fiction RPG with FPS gameplay)...all of those things work GREAT for me so I love it. The inventory system could be better, but IMO that's nitpicking in the scheme of things.
I can vouch for Gamefly too that their stuff is usually in excellent condition (often looks new), and the manual and case basically ARE new-they're just set aside when they get the games so they can be given to someone when they purchase the game. (And as mentioned, you get free shipping if you've got a subscription to them-and you can even just rent the game from them and then choose the "keep it" option to buy it and you'll keep that copy and they'll send you the case and manual and next rental.)
This is the version to get since the PC version requires "activation" (and it's LIMITED activation on top of that!) Sure the PC version would look even better, but IMO this still looks and plays great.