> Warren Buffet would never spend such a ridiculous amount of money on a watch.

He has apparently at least a 40k+ watch. [1]

[1] https://www.scmp.com/magazines/style/luxury/article/3215841/...

The thing with a $500k watch is it keeps its value. It might even increase in value. So it's not a frivolous waste of money, you can get most of it back unless you break or lose it.