Sure, I guess the assumption is that those "dollars away" also include the money to run a whole lot of unmanned flights, a bunch of manned-but-risky flights and

Sure, I guess the assumption is that those "dollars away" also include the money to run a whole lot of unmanned flights, a bunch of manned-but-risky flights and have some failures (hopefully of the unmanned kind) in the process of making the whole thing repeatable.