Re: Rocket cost
"But for larger missions to send significant payloads to the Moon, Mars, and other distant places, the cost of the actual launch is a much, much smaller proportion of the overall cost. "
Yes and no.
The high cost of launchers drives projects to make everything _perfect_ and to pile as much as possible into one mission.
The result is hundreds of prototypes and a shitload of stuff piled onto one spacecraft.
Cheaper launchers would mean more tolerance of failure, which in turn means that fewer prototypes can be churned out and possibly more spacecraft contemplated.
As one example it's been floated that perhaps a dozen Beagles could be built and scattered across Mars. We pretty much know why the original failed (the airbag, resulting in a hard landing, resulting in it not opening) and if it had been properly funded then it wouldn't have been sent out with a used (and patched, and still full of ice crystals) prototype airbag fitted. The cost of a dozen Beagles would be around twice that of the original one and the hard part then becomes hitching lifts on passing spacecraft.