If Warren Buffett is indeed still paying only $3 for breakfast every day, that's giving a big middle finger to the economy. Money is half of the circulatory system of the economy. When it pools too long in one spot, it clots, and then a thrombosed clot can cause damage somewhere else.
He really needs to spend more on breakfast. As one of the richest individuals on the planet, even if he just wants a sausage muffin, it should really be made from only the highest quality agricultural goods, with a lot of personal services added. If he can't manage to swallow that level of ostentation, buying thousands more of the consumer-grade item than he could eat personally would also work.
The only reason for poor people to permit rich people to continue existing is that concentrations of wealth allow for the development of novel classes of goods and services. There would be no luxury yachts if nobody could afford more than a fishing reefer. There would be no Acura if nobody could afford more than a Honda; no Lexus above Toyota; no Cadillac above GM. The luxury goods and services are the early adopters. Without them, some technologies would have died at inception, never to make it to consumer-grade products, because they were too big and expensive.
Anyone can spend small. Everyone else needs the rich folk to spend big, whenever they can. If you don't buy the best, you are not doing your job as a rich person. If you aren't spending on someone's wage, you aren't really "creating jobs". If you can afford to have your cabinets painted instead of doing it yourself, hire someone for that and get back to being the QC/beta-tester for humanity's R&D. This crap where you "retire" and pretend to be rustic and homey isn't helping anyone. If you want to live like a poor person, that's easy; just get rid of all your money. Give it to someone more willing to spend it.
Frugality stops once you can pay all your bills from your paycheck and still have some left. After that, it's called stinginess or miserliness.