Amazon Arma II CO $7.5

Not a Steam version.

Check the feedback!

"Is This download game available in steam?
It does not activate on Steam.
May 17, 2012 by Fahad A. Naeem | See all 11 posts"

I thought so :(
So, will I be able to play DayZ ?

You don't need to have the game on Steam to play DayZ. :)

http://dayz.gamepedia.com/How_to_install_DayZ#DayZ_Non-Steam_manual_installation

Thanks, one more question, am I able to buy 2 copies for me and my friend?

Thanks for the heads-up! I've got a standalone, non-Steam version (GOG) and was getting frustrated over a lack of sales for the expansions, and two of them are also listed from that page for a couple of bucks apiece. Now I've just gotta find the Czech Republic expansion on sale somewhere (and man, I like Desura, but their prices for the Arma stuff are really high).