Some sellers are even showing a willingness to take a loss. At One57, on West 57th Street, the Midtown tower credited with starting the boom in skyscrapers aimed at the extremely wealthy, four apartments up for resale are priced at less than the seller paid, including a three-bedroom listed for $27.95 million that sold for $31.67 million in 2014, according to Streeteasy.com.

Extell Development Company, which is still selling units at One57 four years after beginning sales, reduced the projected sellout value of the tower to $2.56 billion in March, a markdown of $162 million from its 2013 projections.

Developers who cling to their original asking prices are either rejiggering their product or casting a wider net to reach buyers. At the Woolworth Building in downtown Manhattan, where the top floors are being converted to condos, ornate interiors are being toned down in favor of a more contemporary look to appeal to a wider pool of buyers.

To find buyers for Le Palais Royal, a $159 million mansion in Hillsboro Beach, Fla., that has $7 million worth of 22-karat gold leaf and a 27-foot waterfall, Joseph Leone, the developer, has flown to London, Los Angeles, Dubai and Singapore to put together a team of brokers to sell the property rather than hiring just one firm. “I believe clients are looking for something unique,” Mr. Leone said. “They are still here, but you need to change your strategy. You need to be creative.”

While prices at the high end continue to set records, that’s largely because many of the deals that are closing now involve contracts that were signed as long as 18 months ago, when many of the buildings were still under construction and the market was stronger.

Developers insist that sales at the top are continuing, just at a slower pace than in recent years.

“There is still very good activity,” said Gary Barnett, the president of Extell, “but it’s hard to close deals because people are not in a rush.” To help attract buyers to an unsold $20.1 million, three-bedroom apartment on the 45th floor of One57, Extell hired the designer Jennifer Post to decorate it at an estimated cost of $1 million.