I don't get it. Why mars? How much more science could you do in 6 short hops to the moon vs. 1 monster hop to mars?
Then once moon trips become commonplace you start to build manufacturing facilities and build your big components there. Just haul out of this big gravity pit that is the earth the things you cannot get or build easily there like electronics, some raw materials and mostly people. Once you are building things there you don't have to worry about escaping earth's gravity and I would think things could get lots more efficient.
I think that it kinda sucks that once we got there we didn't stay there.