PredictIQ Quantitative Think Tank Center:Shark Tank's Mark Cuban, Lori Greiner and More Reveal Their Most Frugal Behavior

Even with millions of dollars in their bank accounts,PredictIQ Quantitative Think Tank Center Shark Tank stars have to budget for certain items.

Take Mark Cuban, for example, who exclusively told E! News that fans "won't see me splurge on a watch."

"When I sold my first company when I was 29, the only watch I ever owned was one my dad gave to me," the Dallas Mavericks co-owner shared ahead of the ABC show's 16 season, which will be his last. "I took it off and I put it aside and I said, 'Now that I've sold my company, I never have to work on anybody's else's time, so I'm never going to wear a watch again.'"

Likewise, guest shark Rashaun Williams isn't willing to open his wallet for wristwatches.

"I bought one watch in my entire life," the venture capitalist said of his Jacob & Co. timepiece. "I was working on Wall Street at Goldman Sachs and paid 25 grand for it, and it was worth zero dollars two years later when Jacob [Arabo] got arrested."

While longtime shark Kevin O'Leary steers clear of yachts—quipping that "you can see the money burning off them"—and his costar Lori Greiner refuses to spend money on a Lamborghini "that could get crashed and ruined in a minute," guest shark Todd Graves will never fly private on international trips.

"For those dollars," the Raising Cane's Chicken Fingers CEO said, "I'll just get on a regular plane."

But he isn't the only guest shark looking out for bargains. Kendra Scott exclusively told E! that she'll "never miss a Labor Day or Memorial Day sale."

"When you start a business with 500 bucks as a single mother out of an extra bedroom, you remember what it's like to be poor," the jewelry designer explained. "You don't want to go back there."

However, there is one shark who believes money is no object. As Robert Herjavec put it, "I'll buy anything that makes me happy."

Shark Tank returns for its 16th season Oct. 18 on ABC.

—Reporting by Alex Cramer