"flying Trump on an old, outdated Air Force One could be a good thing...."
How short memories are.
The current 747s are still spring chickens. SAM 26000 was in service from 1962 to 1998 and SAM 27000 from 1972 to 1998.
ISTR a large amount of grumbling about the flyaway cost of SAM28000 and SAM29000 back in Reagan/Bush days too. It didn't stop them being built.