Difference between the 505 and other versions of ArmA 2

This is bothering me and I know there is a post out there somewhere, but I don’t know what to look for besides 505… I finally got the game a few weeks ago from Best Buy here in Colorado, but it wasn’t the 505 version, but instead is from Got Game ENT and Idea Games. So what is the difference from the 505 versions of the other ArmA2 games..?

I feel like I've been ripped off by a legitimate company, a felling kind of like buying the collector’s edition of a game that includes something special that the regular version of the game doesn’t.

There is none.

Phew, instead of feeling like I got ripped off I feel like an idiot for asking, thanx bud :)