It's actually easy to spend $400 million per rocket. Just agree that you're going to build only 10 of them, and they all have to complete flawless flights.
That's how you spend $400 million per rocket. It doesn't matter who you are. That's artisan construction for you.
It's incredible that we're transitioning into the age of mass production of super heavy lift rockets. Consider the mass production of steel, of cars, of food, and so many other things that fundamentally changed the human experience. Then Elon throws reuse on top of it. Bonkers.
Hmmm. Reusable steel? Done. Reusable cars? Done. Reusable food? Hmmm.