Has a metropolis ever had such a lengthy era of debauched prosperity? Will the bubbly prices of hard-boiling uptown real estate ever simmer down?

No.

According to a source, an apartment at the newly-refurbished Plaza Hotel has gone to contract for at least $50 million, which quite easily makes it the biggest apartment sale ever in New York City.

Since late 2005, that title belonged to the sharp-tongued hedge fund sovereign Daniel Loeb, whose full-floor penthouse at 15 Central Park West reportedly cost $45 million. It isn’t clear if this mammoth Plaza deal, like Mr. Loeb’s, is for a combined-unit apartment--but Stribling broker Sassy Johnson has said that some buyers are combining up to five units each.

Marx would be livid! But The Plaza has always been a land of miraculous, magical affluence: Eloise mixed stiff martinis for Truman Capote in the Grand Ballroom, while Frank Lloyd Wright took his Oak Room tea with Alfred Gwynne Vanderbilt, as Prince Alwaleed bin Talal and Sinatra waltzed beneath the Palm Court’s stained glass.

But things have been different since August 2004, when New York developer El-Ad Properties, headed by the Israeli-born developer Miki Naftali, bought the Plaza for $675 million. El-Ad is spending $400 million to refurbish the 805-room hotel: When it opens in October, the Central Park landmark will have 182 private condos and 130 hotel rooms--plus 152 units that owners will live in for about a quarter of the year before renting them out.

What is the best new perk? “One touch, high resolution, wireless flat-panel display provides each resident with a fingertip array of concierge and security services,” says the Plaza’s Web site, “as well as the ability to simply and elegantly control the interior ambience of their apartment.”

One-touch ambience must be hip because, according to the New York Post, the Plaza has already lured real estate kingpin Harry Macklowe (he paid around $35 million); Bear Stearns C.E.O. James Cayne and race-car mogul Flavio Briatore (both around $25 million); Tommy Hilfiger (under $18 million); and synthetic-faced Jocelyn Wildenstein (under $10 million).

But because the building is still under construction, buyers have had to buy their apartments without seeing them first-hand. According to Bloomberg News, a Russian tycoon and his daughter walked away from the Plaza’s penthouse because sales agents refused to show it. (As recompense, there’s video and digital imagery of the interiors.)

Could the record-breaking buyer have signed a contract without seeing the goods? Surely the bespectacled billionaire J. Christopher Flowers, who paid $53 million last year for the Harkness Mansion, got to see the place before making an offer.

Until now, Mr. Flowers’ purchase was New York’s only single-residential deal to rise above the debauched $50 million mark. Could the Plaza sale beat Harkness? And just who is the buyer? A spokesperson for El-Ad Properties would not comment.