The Arma 2 Complete Collection includes the game and every piece of downloadable content, including those necessary for the game's DayZ Mod, for $39.90, according to a post in the Bistudio store.
In addition to core game Arma 2, the collection contains Operation Arrowhead and Private Military Company, which are required for the mod, as well as British Armed Forces and Army of the Czech Republic. The game is only available for Windows PC and is 25GB.
The Arma 2 Complete Collection is available for purchase in the Bistudio store. Arma 2's DayZ mod has also inspired a standalone project of the same name. A recent developer diary showcased the game's loot, map and clothing mechanics.