The first stage is 80-90% of the value of the whole rocket. If they can just gas-and-go.. well, ask your boss what would happen to the business if you could make 80% of the costs go away....
Yes this is very high compared to many other launchers. The Falcon 9 uses one modified version of the first stage engines, a copy of the same computers, tankage made on the same tooling etc.
Biting the hand that feeds IT
