Can i build a Gaming PC for $500 that can run DayZ on medium settings?

Can i build a Gaming PC for $500 that can run DayZ on medium settings?

Right now, Dayz is a optimization nightmare, becasue its a mod. The Standalone game will come out this month sometime (maybe later) and that will be much better to base a build off of. 
Keep in mind that Dayz is kind of not very fun right now because of the hackers and bugs ect.
My Advice is to wait for the standalone game and come back and we will be able to give you a better idea if 500 is possible
:) 

http://teksyndicate.com/videos/build-best-550-pc-nov-dec-2012

Get a 7770 instead of the 7870 to save the $50 or dont and have a better rig.

Becasue honeslty the main games i want to play when if i get a Gaming PC are Counter Strike games, Chivary, Arma 2, DayZ, and those other steam indie games!! I have an xbox to play the COD's and battlefeield and games of those types so i don't need a crazy highend computer!! Thats why i want to keep it under 500 dollars!!