Some of the world's wealthiest people are surprisingly frugal. Perhaps that's why they're so rich in the first place.
Take Warren Buffett, who lives in the same home he bought in 1958 and still uses coupons.
Here are more frugal habits of Buffett and four other millionaires and billionaires.
Comedian and former host of NBC's "The Tonight Show" Jay Leno plays it safe when it comes to money. From the moment he entered the working world, "I always had two incomes," he tells CNBC Make It. "I'd bank one and I'd spend one." And he made sure to spend the smaller amount.
Leno continued relying on this strategy even after he started hosting "The Tonight Show" in 1992, even though he reportedly earned as much as $30 million a year at the height of his career.
"When I got 'The Tonight Show,' I always made sure I did 150 [comedy show] gigs a year so I never had to touch the principal," Leno says. "I've never touched a dime of my 'Tonight Show' money. Ever."
On his five-minute drive to his office in Omaha, Nebraska, which he's been doing for the past 54 years, Buffett stops by McDonald's.
Depending on how prosperous he's feeling, he orders one of three items: two sausage patties for $2.61, a sausage, egg and cheese for $2.95 or a bacon, egg and cheese for $3.17.
Buffett's not the only billionaire who eats at McDonald's. Bill Gates and Mark Zuckerberg are also fans of the American classic.
The "Shark Tank" star and owner of the Dallas Mavericks has always been careful with his money.
When Cuban was younger, "I did things like having five roommates and living off of macaroni and cheese, and I was very, very frugal," he tells Money. "I had the worst possible car — those types of things."
But "other than that, I've lived in the same house for 18 years and still have the same cars. Other than the plane, which is a big splurge, I'm still a slob. Not all that much has changed."
"Right now I live in an Airstream," he tells Guy Raz on an episode of NPR's "How I Built This" podcast. "I just love it because there's so many random, amazing things that happen around the campfire at night. I think of it as the world's largest living room."
The multi-millionaire says that he prioritizes spending on experiences over things. Plus, his housing choice enhances his creativity, he says.
When launching Spanx, which would become a billion-dollar business, Sara Blakely kept things lean. "I only spent what I absolutely needed to," the entrepreneur tells Money. "The Spanx headquarters was my 1,100-square-foot apartment. I used my roommate's bedroom."
Even when her company started to take off and she had the money to upgrade, Blakely stayed in the same apartment: "For two additional years, that was the headquarters. Then, from there on out, my headquarters were always way below what I could have spent."
"I have that mentality on everything," the billionaire continues. "If I can save money here or there, I'll do it. [Instead of] a very expensive photographer for $5,000 or whatever, I'm gonna go and get a friend and a camera, and we're going to shoot the pictures ourselves."
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