With a combined fortune rumored to be around $50 million, the couple is "worth more than you think," a longtime friend tells PEOPLE in this week's issue.
Banderas "is a shrewd businessman; he has a lot of investments and business interests," the friend adds. "Melanie's no slouch either; they don't spend money they don't have. They are very proud of that."
Both stars continue to act: Griffith just guest-starred on CBS's Hawaii Five-O and Banderas made millions voicing Puss in Boots for the Shrek franchise. Banderas's investments, according to the friend, include commercial real estate in Los Angeles and Miami and overseas – and several restaurants around the world.
"He doesn't brag about it, but if you ask him, he loves to talk business," the friend says. "He loves to talk about what makes money and what doesn't. He's very, very smart and savvy with his money."
Griffith, who asked for spousal support in her divorce filing, and Banderas also have homes in L.A., New York City, Aspen and Spain.
"Obviously, money never seemed to be an issue with them," the friend says. "I don't think you'll find out that they're divorcing over money."
For more details inside the couple's split, pick up this week's issue of PEOPLE on newsstands Friday
Reporting by STEVE HELLING