https://www.pcgamer.com/the-humble-arma-2018-bundle-is-live/

A big box of Arma is now up for grabs at Humble Bundle, and it's a little bit different than the Humble Arma Bundle that turned up in 2017. For one thing, the title is slightly expanded: This is the Humble Arma 2018 Bundle. And for another, there's a little bit more to it. 

For $1, you'll get Arma: Cold War Assault, Arma: Gold Edition, and Arma Tactics. For paying more than the average (which is well over $14 already, by the way), you'll also claim Arma 2, the British Armed Forces, Army of the Czech Republic, and Private Military Company add-ons, and the standalone expansion Arma 2: Operation Arrowhead.