According to Blixseth, the upswing and downturn of local economies has less effect on the prospective Yellowstone Club buyer because there is more demand than product.

TOP VIEW As the overall real estate market has swooned, some high-end second-home markets have bucked this trend. Unusual vacation homes located in markets where growth is limited are behaving differently than real estate in most other classes, and continue to attract interest from enough buyers to keep values growing. Most of these home shoppers tend to be more concerned with lifestyle options than investment value, while speculators are being driven from the marketplace. Alternately, owners of even top-tier homes in areas saturated with them are suffering weakened demand.

"Buyers will pay more for their secondary residence because they spend more quality time in it," Blixseth adds. "In the primary residence, work and school take up most of the day and families often only spend their time together in the evening. In a secondary home, the quality time with family can be a 24-hour experience. All of these reasons combined make for a strong, high-end second-home market."

Limited supply helps explain continued interest in such communities. William Wheaton, a professor in the Massachusetts Institute of Technology’s economics department and director of research at the school’s Center for Real Estate, studies ski resorts and second-home communities. He sees a positive correlation between price strength and supply constraints. The reverse also holds true: Those who purchase more common ski condos in areas where developers can build more will likely see values barely keep pace with inflation, according to Wheaton. "Most second-home communities are subject to lots of development, and when that’s true, the appreciation is not going to be very great," he explains.

This theory may account for the softening market in second-home communities in Florida—even at the high end. For example, home sales of properties priced at $1 million and higher in Naples fell nearly 40 percent in 2006, according to Multiple Listing Service data for the area. In luxury real estate circles, this notion is becoming axiomatic: Rare properties will command greater demand.

Ten years ago, real estate agents in mountain resort communities such as Aspen, Jackson Hole, Wyo., and Park City, Utah, realized that they shared more in common with each other than they did with their colleagues in neighboring towns and cities. This revelation led some of them to form the Rocky Mountain Resort Alliance. The organization markets second-home properties in these areas and tracks real estate data, including aggregate sales figures. Together, the 11 resorts generated a record $11.4 billion in sales in 2005. And, while 2006 sales fell, the alliance remained strong at $10.3 billion. Steamboat Springs, Colo., topped its $605 million in sales in 2005 by about $70 million, while resorts in Summit County, Colo., (including Copper Mountain and Breckenridge) surpassed their $1.1 billion in sales in 2005 by more than $200 million in 2006, according to Dennis Hanlon, president and founder of the alliance. "We’re limited by topography," Hanlon says. "We can’t just scrape into the desert and build another tract house."

The seemingly endless development possibilities in Miami and Las Vegas may explain declines in sales in those markets, according to David Hehman, president of the national vacation-home website EscapeHomes.com. "If it’s not supply-constrained by politics or geography, those markets are going to be very flat," Hehman says.