Bohemia Interactive 25% off Everything Incl. Arma II: Combined Operations
This was posted 10 months 8 days ago, and might be an out-dated deal
Bohemia Interactive are having a 25% off sale for everything in their store, this includes Arma II, Arma II Operation Arrowhead, Arma II Combined Ops. You can also choose from a Steam or Non-Steam version. Personally I had purchased this last fortnight on steam for $30 and it's definitely worth it if you want to try out DayZ!
Arma II Combined Operations Steam Version:
Arma II Combined Operations Non-Steam Version: