Seriously, that's a laughably low "prize". If you could make it to the moon for < $20 million, the US government would have military bases there for cheaper than it costs to build a single fighter jet.
I agree that this is a low amount, but I don't think the goal of a program like this is necessarily to fully pay for the cost of the project. After all, the winner hopefully has a useful asset at the end of it (a spacecraft, or self-driving car, or whatever else). I think it's more of a subsidy: "if you were thinking about designing a spaceship, here's a way to get it done for $20 million cheaper."
