The b2 was 1 billion per plane due to us being stupid enough to buy 20 rather that 300. The entire cost of research, development, and manufacturing had to be recovered with the sale of 20 units. If we bought just 20 f35s they would be 2 or 3+ billion each (and still unable to run, climb or turn). It’s economies of scale. It just simply does not make sense to create a new plane design and not buy a large number of them. The Russians are dumb in their way, but we have our own form of procurement sabotage that borders on lunacy.