True, and that has happened all to often. I wonder how many of the "F-35 is too expensive" crowd are the same that vote for the military-spending/darpa/grants supporting party. Not that it means anything by itself, but the original F22 and F35 orders were enormous, even stuff like the B2s and other aircraft.
It's a catch 22, you get it 2/3rds completed, it already costs 50% more, but if you spend some more money, you get a "finished product", something of value. This has to be far better regulated, we've just started to look into this big-time in the last few years, but it has to continue, and yes it will mean less dollars and jobs for the industry at times, but the past is filled with so much money and so little value...
I don't think we need crazy numbers of these things though, it won't be long before drones "do it all" and can be flown into combat much cheaper. The F35 is really just a stop-gap measure when you think about it. The legacy of the "5th generation aircraft" won't really amount to much for the superpowers IMO.