PLYMOUTH, Mass. — Most open houses feature a hovering real estate agent, a stack of listing sheets, and — if you're lucky — a pot of coffee and some cheese and crackers.

But at The Pinehills, where the koi pond and home movie theater can come standard with a $1 million-plus home, think celebrity chefs and haute cuisine.

To attract buyers, developers of this massive planned community in Plymouth — the town where the pilgrims landed, about 40 miles south of Boston — called in A-list chefs to cook in their new model homes at an open house.

They can't afford not to. High-end houses are becoming harder to sell in some of the nation's hottest real estate markets, which are being flooded with listings as baby boomers downsize. Rising interest rates and energy costs may be scaring off some buyers.

"It's turned from a seller's market to a buyer's market," said Greg Spier, who builds large custom homes in suburban Boston. "The marketplace has become astute. There's more inventory. People are becoming pickier. Maybe there's eight to 10 homes to look at. A year ago maybe there were one to three."

The changing landscape means real estate agents are going to great lengths to attract choosy buyers of these multimillion-dollar homes.

In Miami Beach, agent Zahara Mossman says she uses podcasts to provide online audio descriptions of her listings. She said it's something that sets her apart from competitors and is critical to her success. Potential buyers can go to her Web site, and click into an audio description before deciding on whether to see it in person.

"The competition is fierce," she said. "I have an edge."

Mossman said the market is "as hot as ever," but noted that two of her wealthy clients — "diamond mine people" — recently opted to rent instead of buy a home, convinced that luxury level prices are falling.

"They're going to rent for a year and watch the market," she said. "They have money to buy, they're just cautious."

Warren and Sarah Bland are looking for a new home but are in no rush to buy. They sold their Brentwood, Calif., home two years ago — raking in a gross profit of $719,000 — and signed a three-year lease in Studio City.

"We knew a little over two years ago that we were in a bubble," said Warren Bland. "We felt when we saw the price in Brentwood nearing $900,000, wouldn't it be good to take our profit and rent for awhile."

Bland, 63, author of "Retire in Style: 60 Outstanding Places Across the USA and Canada," said Ithaca, N.Y., which earned high marks in his book, likely is their destination. Several homes listed for $350,000 — nearly double Ithaca's current median sale price — have remained on the market since August. That surprises him and fuels his belief that asking prices will fall.

"We're perfectly prepared to wait until spring," he said. "Prices have stabilized in Ithaca. They may indeed drop a bit by spring."

Since 1975, the average square footage of a new single-family home in the U.S. has increased about 30 percent, according Census Bureau statistics, and is now about 2,400 square feet. Larger homes of 3,000 square feet or more have been pushing the average up. They comprised about 11 percent of new homes in 1988 — and, by 2001, accounted for about a fifth of all new housing.

But in the past few years, the growth has slowed considerably, which may be due to changing attitudes. A nationwide survey by the National Association of Home Builders found in 2000 that half of the respondents would choose more amenities over having a bigger house. Last year, 63 percent responded that they prefer more amenities.

The trend away from supersized homes is one reason big houses are staying on the market longer.

A home on Boston's North Shore that sold in 30 days in the spring might stay on the market four months today, said John McQuaid, who owns and operates Private Properties brokerage, specializing in the luxury home market. Still, he's optimistic that key economic trends — interest rates and employment — will help keep the market from stagnating.

But it's become a buyer's market with more room to negotiate prices.