Considering what you otherwise pay for to defense spending, payment to banks and blowing people in the middle east up, the price of a mission to Mars would be very little.

Literally true. Consider what awesome things could have been built with the trillion spent on Iraq. A space elevator, a mars mission, a moon base. Not or... and!

Even more money was spent on the stimulus. Somehow, it wasn't as stimulating as colonizing a new planet.

Except the stimulus didn't kill tens of thousands and drove many thousands others into extremism. That makes it a far lesser evil imho.

But you already do that. Might as well reallocate some funding.