Mark Cuban says the best thing he ever spent money on was a plane. Reuters With a net worth topping $3 billion, Mark Cuban has money to spend.

Cuban became a billionaire in 1999 when he sold his second company, Broadcast.com, to Yahoo for $5.9 billion. Since then, the business magnate has made several pricey purchases, including buying the NBA franchise the Dallas Mavericks a year later.

However, in a new column for Men's Fitness, Cuban said that the smartest thing he ever spent money on was a private plane.

"It's obviously brutally expensive, but time is the one asset we simply don't own," he wrote. "It saves me hours and hours."

Cuban purchased his first jet — a Gulfstream V— in 1999 for $40 million. Since then, he's added two more to his fleet: a Boeing 767 that he rents out and a Boeing 757, which he uses for the Mavs.

The "Shark Tank" star goes on to say that the most important things in life are family, time, being nice, and avoiding stress, while "trying to have more than the next guy" just isn't worth it.

Though a private jet might seem like a demonstration of opulence, to Cuban it's not about showing off his wealth — it's about effectively using his time so he can attend to what matters.

"It means I have more hours in my day to spend with friends and family," he explained to the Wall Street Journal in 2010. "It means I can get more work done. It means I can travel comfortably with my family. It’s a life- and game-changer."