Personally I think it works fine.
The modern MBT's cost as much as they do because they're Very deadly, and very survivable.
The Attack helicopters cost as much as they do because they have maneuverability on their side and a good punch, if you can get the blasted things to hit...
If you're really convinced that something's wrong (Which I'm not, And I've been playing for just a few years
), then look under preferences. There's a side bar there with lots of fields that you can alter to make something's more or less effective.