ArmA 3 is worth at most $50 and at least $45. I purchased it at the Alpha and even though it's officially released I can honestly say it's in still the beta phase. Don't get suckered in buying a $60 beta.
As many others have said, ARMA is as more of a platform than a game itself, and I got hundreds of hours out if ARMA 2. What it lacks in dev content, it makes up for with a dedicated community, and gameplay you won't find anywhere else.
I'd easily pay more than $60 for what's released now, because I know it will be worth it.
Light travels faster than sound. This is why some people appear bright until you hear them speak.