In the market for a pre-built gaming desktop?

In about the $500 range (i'd say about 400-600). Now, it doesn't have to play Battlefield 4 at max settings with 150 fps. I'm just looking for a pc that will play just about anything at medium settings with little to no lag. Games I know i'll be playing that come to mind are Minecraft, DayZ, Killing Floor. I doubt i'll be playing things like Call of Duty or Assasin's Creed.
I know next to nothing about this sort of stuff, so I need it to be pre-built, playable right out of the box, and in that price range (if there's really nothing that works like this then of course i'll go higher, but obviously I want it as cheap as possible).
*Oh and preferably have Windows 7*
Right now I was looking at this one: http://www.amazon.com/...00D1KX2M4/

Thoughts? Suggestions?

Dude you're better off building your own computer, that computer on amazon won't run you ****, that is an insanely terrible GPU, they shouldn't even call that a GPU, that won't even run you minecraft too well. Honestly bro from building many computers, It's just not worth buying one unless youre in the 600+ range and even then it's not till about 950+ that you would get a computer thats powerful and will last you a great amount of time (excellent quality build). I'm telling you don't buy the pc you will really regret it.

as much as i dislike consoles if youre in that price range you're better off buying a ps4 which is insanely much stronger than that awful computer