Foreign purchasers accounted for about 10 percent of Town & Country's deals in the quarter, with buyers mostly from the United Kingdom, Russia and Germany, Desiderio said.
"Foreign interest has stimulated some of the Americans to pull the trigger, but it's with trepidation," she said.
The year-over-year sales gain may also have been boosted by comparisons to the third quarter of 2010, when sales weakened after the expiration of a federal tax credit for homebuyers, Miller said. The incentive required contracts be signed by April 30 and deals completed by the end of September.
Linda Miller, who put her two-bedroom waterfront cottage in Southampton up for sale in August 2010, said she is starting to see a pick-up in the market.
Miller, who is unrelated to Jonathan Miller, originally listed her home for $1.975 million. She switched brokers in August of this year and cut the asking price to $1.625 million. Since then, she's seen an increase in interest in her property, which comes with a $30,000 boat.
"People have gotten used to the downturn in the economy and, for those who are able, I think people are realizing now is the time to go out and buy," said Miller, 63, who owns a marketing agency. "It's really a buyer's market."
East Hampton Village had the biggest gain in sales prices, according to the Town & Country report. The median jumped 155 percent to $4.85 million, based on seven transactions during the quarter. The median sales price in Southampton Village, where there were 14 sales, rose 43 percent to $2.55 million.
The area with the biggest drop in the median price was Shelter Island, with a 40 percent decline to $790,000. The median sales price in Westhampton fell almost 13 percent to $700,000.