The Viceroy, a swanky condominium complex in downtown Miami, gives the impression that the United States is in another real estate boom. The sales office is strangely exuberant. Buyers gush about the glam condos — designed by hipster tastemaker Kelly Wearstler — and their hotel-like amenities: poolside libations, daily housekeeping and room service food stirred up by a celebrity chef.

Since January, 262 of the Viceroy’s 372 units have sold. But there’s a twist: Almost 90 percent of the buyers are foreigners. And they all paid cash.

The Viceroy’s story is playing out across Miami. Individual investors from as far as Argentina, Canada, Colombia, France, Israel, Italy, Norway and Venezuela are swarming the city’s sales offices to get in on what they see as one of the greatest real estate fire sales in the history of the United States.

At one time, these people would have invested in the U.S. stock market. Now they see the opportunity of a lifetime in the nation’s debilitated housing market. The idea is to rent out the properties and then sell them once the economy turns around.

The math is seductive: Prices at the Viceroy are roughly 52 percent off the 2007 peak. Units once sold for as much $670 a square foot. Today the average price is $319.

“I have never seen such a high concentration of foreign nationals acquiring real estate,” says Peter Zalewski, who has been in real estate for 15 years and founded Condo Vultures, a consulting and brokerage firm. “Eighty percent of the sales in downtown Miami are foreign-based. This is unprecedented.”

Miami is hardly the only hot spot for buyers from outside the United States. Real estate brokers say they’ve seen a surge in Washington, New York, Las Vegas, Los Angeles and San Francisco. In Seattle, Asians are buying property sight unseen, says Joe Brazen of Brazen Sotheby’s International. In New York, 25 percent of buyers at the Armani-designed 20 Pine building, near the World Trade Center site, are from overseas.

This year in Phoenix, for the first time, there have been more buyers from Canada than from California, according to real estate data outfit Information Market. With the Canadian dollar approaching parity with its U.S. counterpart, the opportunity was simply irresistible to Jim Chuong, a 38-year-old Novartis sales manager from Toronto.

Chuong, whose house in Canada is already paid off, used to invest in U.S. stocks. Now he’s investing in Phoenix condos, paying $50 a square foot for units that would cost $500 a square foot in Toronto.