[mikeash]

I recall that they spent about $1 billion in landing-related R&D before they got it to work. Definitely a lot. (Although, for comparison, a single Shuttle cost about $2 billion to build, not counting any R&D costs.)

But if that $1 billion came from their margins rather than from investment, it means they wouldn't run out of funding unless they ran out of business, which is pretty cool.

[snrplfth]

I believe that the $1 billion figure is for the entire development cost of the Falcon 9 vehicle (stages 1 and 2.)