Obviously the final number of F-35's won't be known for probably 15-20 years
Well
it's been known for almost a year that's there's no more money - any cash for future price increases comes from reducing the number bought.
So the F-35 is already into a death spiral; as the price goes up, the number to be built goes down, which drives the price up, which drives the number down..... and so on to the end.
The only question is how many get built before the plug is finally pulled.