War thunder (bomb thunder?) is free to play, and covers slightly pre-WW2 up to very early jets in the bombers, if that would interest you.
You'd start out without much in the way of bombers though, and if you want to keep it on the cheap you'd have to grind a little bit to unlock bombers, and then to unlock improvements to them.
If you're feeling flush you can purchase 'Golden Eagles' - one of the 2 in-game currencies, and spend them to unlock planes, and plane upgrades.
Flying in the 2 more realistic modes rather than 'arcade' should give you a more 'realistic' approach to combat and bombing, but you'd be very much limited to 'dumb' iron bombs, and chucking them at either small targets like individual tanks, or bigger stuff on certain maps like destroyers and battleships.
There is a good range of bombers however, especially on the Soviet tech tree. SU-2, IL-2, IL-4, AR-2 and the (in-game) infamous YER-2 are available.
Oh, and the mighty TB-3 has been available as a gift plane. I own it, in all its' glory.