If someone quoted you $200,000/person for building a 1 million person city from scratch in the middle of the desert, it would be a lowball figure.
The Masdar city in Abu Dhabi was planned to cost $20 billion and house 40k people. That's $500,000/person, right here on Earth where breathable air and protection from cosmic radiation is completely free of charge, and you don't need to launch anything out of Earth's gravity well.
So if Musk had a realistic way of reaching $200,000/person, he could start doing it on Earth and completely fund his Mars project purely from the profits of selling the Earthside city to someone else here on Earth.
I agree he’s probably being over optimistic about the price, unless he has a self-replicating factory skunkworks (which is also entirely plausible), but on the other hand Musk’s estimates are only factor of x2-x3 fantasy compared to subsequent delivered realities, better than the rest of the space sector even when he’s promising more.
I think Gates and Musk have both shown that there's an effectiveness multiple between a single, informed donor and the government as far as funding is concerned.
Government funding is larger in magnitude, but can't be targeted to the same degree and has blind spots.
> The "self-sustaining city on Mars" bit is a pipedream, and not something we should spend serious amounts of money on in the 21st century.
Compared to the roughly $100,000 billion/year combined GDP of all nations, the $8 billion/year [0] Musk is trying to make the Mars colony cost is a rounding error, not “serious” money.
[0] 1e6 people at $200,000/person, divided by 25 years for even the most optimistic timeline