Ah yes, I was going to tell you about this juicy detail: you don't need the DLC to get the DLC achievements! 1750 right from the regular disc. So if you go on eBay spring for the regular edition if its cheaper.
I don't actually, as I heard the copy I used has gone missing (i'm in the clear though, this was after I borrowed it )
If you do get ahold of a copy make sure your PC (or the one you use) can handle it, as they let you install it, but not start of the game if your computer isnt up to specs. And make sure you understand the GFWL Live client for your PC if you don't have it already.