[xanderstrike]

The difference probably has to do with the fact that SpaceX has a functional revenue model beyond what's essentially a pre-order. Further down in the Wikipedia article for SpaceX, as of 2012 they had taken in over $4 billion in lifetime revenue. Also, they got a $1 billion investment from Google and Fidelity in exchange for 8.333% of the company this past January.

I think the answer really is money, SpaceX has more of it because it has built a product it can actually sell right now.

[1] http://en.wikipedia.org/wiki/SpaceX#Funding

[mikeash]

That seems backwards. They didn't have ongoing revenue until they proved themselves capable. Their early days were a similar situation to Virgin Galactic now, but, apparently, with even less money and doing harder stuff.