In the world of high-end real estate, it can be tough for other cities to keep up
with Manhattan and Beverly Hills, with all the star power and headlines generated by 20-something heiresses paying more than $80 million apiece for trophy homes — a kind of bicoastal battle of blank-check buyers.

But don’t count out South Florida. The high-end market in Miami-Dade County may not have a Petra Ecclestone or Ekaterina Rybolovleva jetting in to spend money from her billionaire father, but its selling environment, once synonymous with bust, is seeing signs of a boom again.

Two weeks ago, a penthouse owned by Alex Birkenstock (from the German shoe company loved by the hippie crowd) sold for $25 million, a record apartment sale, to an Italian who controls an investment company. In recent days, a developer’s 10-bedroom home on the exclusive Indian Creek Island, listed for $52 million, went into contract to a foreign buyer, brokers said. The price was not disclosed.

If that deal closes, it will very likely top the post-bubble record for a residential property sale in Miami-Dade County, currently held by Edward Lampert, a hedge-fund billionaire, who bought a house on Indian Creek in March for $38.4 million, brokers said.

“Everything is kind of selling now,” said Jill Hertzberg, one half of “The Jills,” a broker duo for Coldwell Banker in Miami who are co-listing the 10-bedroom home, at 3 Indian Creek Drive, which features a “7-limo-size” garage.

“You wonder how long it will last,” Ms. Hertzberg said.

The pending sale on Indian Creek — home to Julio Iglesias and Norman Braman, a billionaire art collector and former owner of the Philadelphia Eagles — is the latest in a string of homes and lots that have sold on the island over the last three months. All of the sales have been over $10 million, and most have been by longtime residents acquiring neighboring properties.

New listings are carrying enormous price tags. The steel magnate Leroy Schecter recently put his 21,746-square-foot home on Indian Creek up for sale for $45 million. This week, Ian Bruce Eichner, a New York developer, raised the listing price of his 11,031-square-foot penthouse at Continuum towers in Miami Beach to $39 million from $35 million, to be “in line with the market,” said Dora Puig, the listing agent.

“This has been a market-moving year for Miami Beach,” Ms. Puig said.

It wasn’t always like this. Since 2006, when housing prices peaked, Miami has been widely viewed as the “poster child for distressed real estate,” with two-thirds of all sales being distressed as recently as 2010, said Jonathan J. Miller, the president of Miller Samuel, a real estate appraiser.

But price jumps at the high end of the market are sharply outpacing the rest of it. The average price of a single-family home in the top 10 percent of sales — over $1.75 million — rose 22.1 percent over the past year, versus 4.5 percent for the overall nondistressed single-family segment, Mr. Miller said.

The run of big sales and bigger price increases started in December with a penthouse at the Setai Resort and Residences that sold to Kenneth C. Griffin, a Chicago hedge-fund billionaire, for $21.5 million, a record at the time.

“That lit the fuse,” Ms. Puig said.

Then, in February, Alberto Bulus, the son-in-law of a wealthy insurance family from Rio de Janeiro, bought a 6,100-square-foot apartment in the Continuum for $16.2 million. (Mr. Bulus also owns a triplex penthouse of some 14,000 square feet in the Ipanema neighborhood of Rio overlooking the ocean, according to O Estado de S. Paulo, a Brazilian newspaper.)

At the Apogee, another luxury condo complex in Miami Beach, an apartment bought by a Russian couple for $11.5 million in April of last year is now listed for $25 million.

Ms. Puig said one of her listings, a penthouse at the Icon condominium, in South Beach, recently went into contract to a Latin American buyer above the asking price of $19 million.

On Indian Creek, just north of Miami Beach, the buying and selling pace has been faster than a cigarette powerboat. A half-dozen lots and homes have traded since last July, four since March. The village is among the most exclusive in the country, with only 32 houses surrounding a top golf course. Other residents include the Brazilian supermodel Adriana Lima, the former Miami Dolphins coach Don Shula, the billionaire investor Carl Icahn and Mario Luis Kreutzberger Blumenfeld, a TV presenter known by his stage name, Don Francisco.

The security on Indian Creek is tight. Unlike Star Island, which I visited in February, it has restricted access, because the road leading in is owned by the country club. A police force of 10 sworn officers protects 86 residents. The village even has its own 24-hour armed boat patrol.

All the homes are on the water. Mr. Schecter’s home has 7 bedrooms, 14 bathrooms and 200 feet of waterfront. He listed it for $32 million in 2008 and raised the price that year to $35 million before taking it off the market in 2009.

The recent spate of sales, including the record-breaker to Mr. Lampert, who lives next door, justified the $45 million asking price, said Nelson Gonzalez of EWM Realtors, the listing broker.

(The 85-year-old Mr. Schecter, who has pledged to give 90 percent of his wealth to charity, also owns two apartments on the 35th floor at 15 Central Park West, one of which he rented to Alex Rodriguez of the New York Yankees. They are being renovated, a spokeswoman said. Last year he tried to sell them together for $55 million.)

Lately, longtime residents of Indian Creek have been doing most of the buying. Earlier this month Mr. Iglesias bought an 80,000-square-foot lot for $15.2 million; he now owns nearly 7 acres, Mr. Gonzalez said. At least two others, including Robert Diener, a co-founder of hotels.com, and Jaime Gillinski, a Colombian banker, have also bought more property there this year.

“It really is a couple of families that are trying to control the island,” said Oren Alexander, a broker with Prudential Douglas Elliman who is co-listing 3 Indian Creek Drive, the home listed for $52 million that is now under contract. (His father, Shlomi Alexander, built the home.)

Or they are simply realizing that one day soon there won’t be any more waterfront property on which to build new trophy mansions — no matter how much an heiress is willing to pay.

“The future of extremely high-end real estate in Miami Beach,” Mr. Gonzalez said, “will be land.”