Jorge Perez, noted Miami philanthropist, art museum namesake, and real estate developer, is looking to unload his luxurious Miami Beach digs in the recently completed One Ocean, and if the savvy billionaire has his way, he’ll make a pretty penny on the close. That’s because Perez bought into his company’s development in 2012 when the South Florida real estate market was still cool from the 2008 recession.

“We started selling One Ocean in 2012 at $1,100 psf, which seems crazy today,” Perez said in a statement. “We’re very proud of the neighborhood and value we created for Miami Beach, particularly South of Fifth.”

Perez will be banking that the market agrees with his assessment of that value. His ask on the luxurious penthouse apartment is $20M—a four-fold increase over the purchase price.

One real estate broker thinks the price may be a bit unrealistic. Eloy Carmenate of Douglas Elliman Real Estate said “it’s not aligned with the market, not at $20 million.” Indeed, that would put the 7,500-square-foot apartment at $5,669 a foot. To put that in perspective, that’s more than double the median price per square foot for Manhattan’s most expensive neighborhood, Central Park South.

Pérez was born in 1949 in Argentina to Cuban parents of Spanish origin and lived in Colombia before moving to Miami in 1968. His net worth is estimated at $3.8 billion.