Real estate broker to the stars (and under-the-radar big shots) Stephen Shapiro has a listing for a mega house on Carbon Beach in Malibu. The asking price: $65 million. The owner isn’t a celebrity, but a low profile mogul named Bill Chadwick, co-founder of the Westside real estate investment firm Chadwick Saylor & Co. and president of the Coliseum Commission. The 1O,500-square-foot Cape Cod style house has 150 feet of beach frontage, a home theater, wine cellar and six bedrooms. Over the years Chadwick has built two other homes on exclusive Carbon Beach and sold them, “much to his wife’s chagrin,” Shapiro joked. “It’s almost like a hobby.” Carbon Beach neighbors are said to include David Geffen, Haim Saban, Larry Ellison and Jamie and Frank McCourt, among others. “It’s referred to as ‘billionaire’ s beach,’ “Shapiro said. Shapiro, chairman of Westside Estate Agency, also lives in Malibu, but not on Carbon Beach . “I can’t afford Carbon Beach. Most people can’t.