“Everything on the lower end of the scale was either a total teardown, which would make a mortgage impossible, or in an undesirable area,” said Mr. Maplestone, 34, a video editor based in Brooklyn.

They had all but given up the hunt earlier this year when Ms. Fisk, 32, a sales strategy director, found an online listing for a $499,000, two-bedroom house on nearly half an acre in Montauk that had just been reduced. Not only was it in walking distance to the beach and town, the yard abutted nearly 40 acres of protected land, ensuring privacy.

“I had a contractor take a look to make sure I wasn’t missing something because I thought for sure this was too good to be true,” Mr. Maplestone said. The couple bought the house for $450,000, put in a new kitchen and bath, doors and windows, and began using it as a weekend getaway earlier this month. “We definitely feel we got a deal,” Mr. Maplestone said.

Not so long ago, half a million dollars wouldn’t buy half an acre in much of the Hamptons. But now that the market has recalibrated and prices have begun to stabilize, a growing number of modest but more affordable properties are popping up for $500,000 or less, creating opportunities for second-home buyers who were previously priced out.

“It’s slowly begun to come back to where prices are of relative value and people can justify them,” said Joseph De Sane, a senior vice president in Corcoran’s Bridgehampton office. He pointed out some listings he called “top values,” including a four-bedroom renovated Cape for $499,000 on nearly an acre at the edge of East Hampton Village that recently went into contract and a $455,000, move-in-ready three-bedroom with central air-conditioning, hardwood floors throughout and a large deck spanning the full width of the house in North Sea. “We’re seeing a bit more in the way of quality,” he said.

There were 720 homes listed for $500,000 or less in the second quarter of 2012, down slightly from the same period last year, but up 11.8 percent from the second quarter of 2010, according to StreetEasy.com. The median listing price was $385,000, down slightly compared with the second quarter of 2011. Though most homes for less than half a million are small, you can now get slightly more space for your money. The size of a home in that price range increased by 10 percent to 1,102 median square feet in the second quarter of this year compared with the same period in 2010, according to StreetEasy.com.

Sure, more affordable places have long been available in less-sought-after neighborhoods west of the Shinnecock Canal, including the hamlets of East Quogue and Hampton Bays. But attractive properties are now available in more coveted locales east of the canal, which cuts across the South Fork at Hampton Bays, demarcating the more exclusive hamlets and villages running from Southampton to Montauk.

Take the well-maintained three-bedroom cottage with a wraparound deck on a shy half-acre a block from Otter Pond, tennis courts and Main Street in Sag Harbor Village, listed by Sotheby’s International for $480,000, recently reduced from $499,000. Or the three-bedroom with an updated kitchen, gas fireplace and large backyard in Southampton Village, listed by Prudential Douglas Elliman at $495,000, down from $549,000 in 2011.

Outside the villages the deals get better, including larger properties with more amenities for less money. Consider a refurbished three-bedroom, two-bath Southampton home with a wood-burning stove, eat-in-kitchen and a new deck near Big Fresh Pond, listed by Corcoran for $420,000. Or a three-bedroom, two-bath contemporary in Clearwater Beach, a private beach community in East Hamptons Springs, with central air conditioning and a heated pool on nearly an acre listed by Corcoran that was reduced by $20,000 to $495,000.