Buffett is pretty consistent in living modestly in all aspects. He lived in the same house in Omaha from 1958 - 2022, which asked $877,000, which a lot less that a lot of Zen monasteries, if for no other reason than the monasteries house more people. But monasteries have a tendency to be pretty nice: you have to house a bunch of people, and the non-monks tend to donate money over time. Buffett is known for modest living. I think corporate headquarters now employs 10 people (market cap of almost $700 billion). He's pledged to give away all his money by the time he retires, and has already spent quite a few years giving it away, which is why he's down to a net worth of $99 billion.

He's no ascetic: he enjoys a good steak (and tons of Coke) and he had an $11 million vacation house. But fairly modest, especially for someone who has voting control of a $700 billion corporation (which he built from pretty much nothing).