I don't think half the things he says about his frugality are true.

I'm reminded of how Clarence Thomas used to have a similar reputation ("he drives around in an RV for vacation!"), but then it came out that he was taking a bunch of bribes involving private planes and yachts.

He doesn't live in destitution of course. But a million dollar home and a beach house is easily attainable for a surgeon or corporate lawyer. And you gotta remember, a billionaire has the net worth of a thousand doctors. And Buffet has over 100 times more on top of that.

Also, it says nowhere that it's the only house he owns. It's absolutely possible that it's something he just hoards, like a drawer full of knickknacks you haven't seen the inside of in a decade, and of comparable relative worth to him.