Evan Joseph/Prudential Douglas Elliman A condo in the Ice House is listed for $9.5 million.

Moguls and mansions, conquests and prizes, prestige and social status — this is the language of the blood sport that is big-money New York City real estate. And the word “trophy,” as in “trophy apartment,” “trophy building” or “trophy sale,” gets tossed around a lot.

But the working definition has become somewhat slippery.

There are those who contend that a trophy property costs at least $20 million. And that price tends to be the benchmark used when sales, like the recent one of a town house on West 10th Street for $20 million, are reported in the media and talked over by those who like to talk about these things.

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Michael Vargas, a principal and a co-founder of the Vanderbilt Appraisal Company, said he defined trophy properties as those in the top 1 percent of sales, which in Manhattan means $10 million and up. He added that because $10 million sales became almost “commonplace” before the housing crash “and no longer generated any sense of amazement, the $20 million-and-higher sale was generating the market buzz.”

Mr. Vargas said a trophy property had to be “rare, special and coveted by many, like a Picasso.”

On that point there is widespread agreement. But if you ask real estate brokers to put a price tag on a trophy, the answer is all over the place.

This is what Donna Olshan, the president of Olshan Realty, found in a recent survey of colleagues from other firms asked for their answer “if a customer walked into your office today and asked, ‘I want to buy a trophy property, what will it cost?’ ”

The responses, from 16 of the city’s top-selling brokers and 3 appraisers, ranged from $10 million to $45 million. Most gave higher prices for uptown (and for town houses) than for downtown.

One said a buyer would pay $40 million for a trophy apartment uptown but $25 million downtown; another said $12 million for an uptown apartment and $20 million for an uptown penthouse. One said $25 million for an uptown apartment and $15 million for downtown; another specifically said $44 million, which was also the closing price of the most expensive city property sold in 2010, the Duke Semans mansion on Fifth Avenue.

And interviews with five of the city’s top-selling brokers revealed that what makes a trophy can be quite subjective:

“It’s something I can have but no one else can; I own what you want.”

“It’s the one penthouse.”

“It’s custom-designed.”

“The architect makes it a trophy.”

“The address makes it a trophy.”

“My neighbors are famous.”

“Famous people once lived in my trophy apartment.”

“It’s a trophy because it’s an apartment in 15 Central Park West.”

(Or, it’s not a trophy in 15 Central Park West because it is not the $40 million penthouse sold late last year by one of the condominium’s developers, William Lie Zeckendorf.)

Dolly Lenz of Prudential Douglas Elliman, one of the best-known brokers in luxury real estate, said she could not put a price on a trophy. She said that a trophy was “without peer,” and that if an apartment was identical to another, even if it was in what many considered a trophy building, it could not be a trophy. She closed one of the biggest deals of 2010, the $31.5 million sale of a penthouse at Superior Ink in the West Village, designed by Robert A. M. Stern and often described as a trophy building.

But Ms. Lenz said one of her current listings, a penthouse at the Ice House condominium in TriBeCa owned by Martha Stewart’s daughter, Alexis, is a trophy — even with an asking price of under $10 million — because there is no other apartment like it. (And the $9.5 million asking price, even though it has been cut several times, would put that property close to Mr. Vargas’s $10 million yardstick.)

Paula Del Nunzio of Brown Harris Stevens, who in 2006 handled the $53 million sale of the Harkness Mansion on the Upper East Side, the most expensive sale of a single New York City residence on record, said a trophy was mainly “defined in a buyer’s mind.”

It depends, she said, on “the incredible assets the buyer would have — great space, outdoor space, great high ceilings in salons and rooms, a great location.”

Asked if one could find a trophy in Manhattan for, say, $5 million, Ms. Del Nunzio sounded befuddled and said she doubted one could find those assets in anything under $10 million. “I guess you could have a trophy one-bedroom,” she said.

But Sharon E. Baum, a broker specializing in high-end properties for the Corcoran Group, said she had seen properties for under $10 million that she considered trophies. “Trophy for 99 percent of the people means expensive,” she said. “But it’s like everything else, money doesn’t necessarily create taste.”

John Burger, the top-selling broker for Brown Harris Stevens in 2010, said apartments could be trophies simply by virtue of their address. “Yes, at 820 Fifth or 2 East 67th, every apartment is identical, every floor is identical,” he said. “But in those cases there is no other building like it.”

Howard Margolis, the Prudential Douglas Elliman broker who handled the sale of a $33.18 million penthouse at the Trump International Hotel and Tower at 1 Central Park West last March, said he would find it difficult to consider anything a trophy that cost less than $4,000 per square foot, or $20 million over all.

Prudential Douglas Elliman An empty penthouse at 1 Central Park West sold for $33.18 million.

Michele Kleier, a co-president of Gumley Haft Kleier, a boutique firm specializing in luxury properties, said that before the housing crisis she would have put the price of a trophy at $25 million and higher, but that she now put it at $15 million.

Answering the question she posed to the other brokers, Ms. Olshan, who along with her survey produced a detailed report on the 2010 sales of residences for $10 million and higher, said she firmly believed trophies started at $20 million.

“The definition of a trophy property may be debatable,” Ms. Olshan added. “But one thing is certain: You have to have trophy money to buy a trophy property.”

E-mail: bigdeal@nytimes.com