Josh Flagg is cashing in on Miami heat … listing his $10 million estate directly across from The Beckham’s $72.3 million compound … TMZ has learned.

The “Million Dollar Listing” star listed the place ten days ago … a Mediterranean-style estate he gutted and rebuilt with BuiltIN Studio’s Gary Eisner. The 4,000 square foot home on a 10,000 square foot lot features 4 beds, 5 baths, vaulted ceilings, custom steel doors, serious security, and a detached pool house with a sauna and cold plunge.

Josh tells TMZ … the home has been rebuilt from the ground up … essentially a brand new house. He says construction is in the final stretch and the buyer will be able to move in within about sixty days.

The property is owned by Flagg Family Capital, the family’s private real estate investment arm, in partnership with Carolwood LP. Headed by Adam Rubin and Andrew Shanfeld.

He says the timing was intentional, saying … “The minute New York elected Mandahmi, I called my broker Jordan Karp. I didn’t even wait for the acceptance speech.” Karp listed the property and his phone’s been blowing up ever since.

North Bay Road, often called the Fifth Avenue of Miami Beach, remains one of the most coveted streets in the country. Flagg’s estate has been completely rebuilt, a rarity in a neighborhood where many homes still date back to the 1930s.

North Bay Road, nicknamed “Billionaires’ Row.” counts David and Victoria Beckham, Michael Bay, Barry Diller and the Von Furstenberg family, and Steve Witkoff among its heavyweight residents with sales regularly topping $70 to $100 million.

Flagg says the Miami rush is predictable. One politician says they’ll “make the rich pay,” and planes at Teterboro start fueling up faster than the Bergdorf sale,” he jokes. “A week later, everyone from Manhattan claims they ‘escaped New York,’ like they tunneled out of Shawshank with a Birkin.”