Exclusive | Tony Florida island with 2 neighboring mansion listings totaling $362M is Miamis rising billionaire bunker

How much does it cost to live large in the Free State of Florida? In this neck of the state, quite a bit.Less than two months after the 13,000-square-foot “Scarface” mansion in Key Biscayne, Florida, hit the market for a breathtaking $237 million, a neighboring compound is being whisper-listed for a cool $125 million, The Post has learned.We hear insurance tycoon Nicolas Estrella Sr., whose fortune was built on an eponymous auto insurance company, is offloading his waterfront lair with Douglas Elliman’s Lourdes Alatriste and Kirsten Smith, who declined to reveal the seller’s identity. The asking prices are stratospheric, but there may be some billionaires who bite.With real estate tight in Miami’s ultra-exclusive Indian Creek Island — the “billionaire bunker” where Facebook founder Mark Zuckerberg recently dropped a record $170 million for an under-construction mansion — the uber-rich have been flocking to Key Biscayne in search of home.And whoever moves in would have some intimate company.Key Biscayne is a 1.25-square-mile island — clocking in at approximately 5 miles long and 1.5 to 2 miles wide — in Miami-Dade County that is home to some 14,000-plus residents.Its composition is two-third parks and one third residential. “Since Key Biscayne hasn’t really been in the spotlight, I think there’s a lot more runway to work with as well as far more upside and more opportunity,” than other exclusive Florida communities like Palm Beach and Manalapan, Smith said.

“Manalapan is the only other market where you’re seeing dual frontage waterfront opportunities and mass assemblages coming into play.”Celebrities have picked up homes in Key Biscayne, including Brad Pitt, Cher and Andy Garcia, the latter of whom still resides there.Key Biscayne draws powerful buyers in part because of its proximity — a 15-minute drive — to Brickell, where billionaires like Citadel founder Ken Griffin, are opening offices.

The island has just one road in ...