I don't see what you are getting at. An enterprise such as sending people to Mars is obviously not going to be made by selling a house or a one time boost from

I don't see what you are getting at. An enterprise such as sending people to Mars is obviously not going to be made by selling a house or a one time boost from a personal fortune, but by setting up a system that allows consistent and substantial profits. Also, Musk's fortune is comes from the shares he owns of his own companies. Not sure it's a smart move to sell all those shares to invest the cash back in the same company.