Shirley Sullivan has been trying to sell her Framingham home since June.

But after reducing the price of her seven-room home from $339,900 to $309,900 and attracting no offers in the last four months, Sullivan gave up. Now Sullivan, who is in her late 60s, will be moving out of the one-bedroom apartment she rented in April and back into the home she’s owned for 29 years.

“I don’t want to say ‘give me what I can get for it.’ I’m not that desperate and I don’t want to go lower than $300,000,” said Sullivan.

Still, she added, “It’s been a little frustrating and discouraging.”

Many other sellers surely are feeling Sullivan’s pain. Single-family home sales in Massachusetts plunged during the third quarter to their lowest level in 15 years.

A total of 14,510 single-family homes sold statewide in July, August and September, 5.5 percent lower than the same months in 2006, according to statistics from The Warren Group, parent company of Banker & Tradesman. Third-quarter sales are the lowest in a third quarter since 1992, when 12,606 units sold.

The median selling price for a single-family home fell 4.6 percent to $315,000 during this year’s third quarter from $330,000 last year.

Some economists don’t think the slump is over yet. With foreclosure activity climbing, analysts anticipate the housing market won’t hit bottom until well into next year.

Foreclosures are big factor in the region’s housing price declines. When foreclosure deeds are excluded from the calculations, the median single-family home sales price for the first three quarters this year is $337,000, down 0.85 percent compared with a median price of $339,900 during the first nine months of 2006, according to The Warren Group.

Problems are expected to continue surfacing in lower-income communities where borrowers with poor credit and low incomes relied on subprime loans. Many of those loans featured adjustable interest rates that will reset at much higher rates, pushing more homeowners who no longer can afford the loans into foreclosure.

“The mortgage crisis with the subprime loans still hasn’t reached its peak. We’re seeing increasing foreclosures as was expected,” said Alan Clayton-Matthews, associate professor at the McCormack Graduate School of Policy Studies at the University of Massachusetts at Boston.

‘Not Horrendous’

Some Bay State communities are bucking the downward trend.

“Some communities are doing well because they’re populated by high-income households that are benefiting by expansion technology sector in the state,” explained Clayton-Matthews, a Massachusetts forecast manager for the New England Economic Partnership. “You can see in certain communities that there’s still construction going on. There doesn’t appear to be a lot more for-sale signs than usual.”

But lower-income communities in Massachusetts are struggling.

“Those communities aren’t doing as well and there are a lot for-sale signs and foreclosures,” he said.

NEEP is predicting that Bay State home prices will continue to fall through the first half of 2008. The economic forecasting group expects prices will be about 14 percent lower than they were during the market’s peak in 2005.

“The main thing to watch is the foreclosure rate, and to wait for that rate to fall to know that the peak has passed. And then conditions will start to improve, or at least stop deteriorating, in some communities,” Clayton-Matthews said.

The median selling price for single-family homes sold during the first three quarters was 4.6 percent lower than the same months in 2006. Through September, 39,805 single-family homes were sold, a 6 percent decline from the 42,398 homes sold during the first three quarters of 2006.

“It’s a challenging market. Yes, sales are down and prices are down. I think the trend will continue. But it’s not a horrendous market. People are still buying; they just need to make quicker decisions to buy,” said Nelson Zide, senior vice president of Whitinsville-based ERA Key Realty Services.

Zide said buyers searching in the MetroWest area have more choices and a wider selection of lower-priced homes.

Of the 309 single-family homes listed for sale in Framingham as of last week, 62 were priced between $200,000 and $300,000. In nearby Marlborough, there were 65 homes in that price range out of 232 listings.

Three years ago, Zide said he would have been able to count the single-family home listings under $300,000 on one hand.

“There was time when if you were looking [for a home] under $300,000 in Framingham, people would laugh at you. Now I have a lot of houses under $300,000,” he said. “Homes in nice areas that you couldn’t have touched under $350,000, you can now buy them for the low $300,000s.”

In Framingham, the median selling price for homes sold through September was $350,000, a 5.4 percent drop from $370,000 a year ago.

Jim Holbrook, senior vice president and manager of Coldwell Banker Residential Brokerage’s regional office in Northborough, agreed there has been an increase of for-sale homes in some MetroWest communities.

“What we’re seeing is that it’s definitely a buyer’s market. Sellers are reducing their home prices and what we’re also seeing is that buyers are really taking their time to pull the trigger and actually purchase something,” he said.

Marlborough, for example, has 10 months’ worth of inventory, he said. The town’s median home price fell 8 percent to $314,000 in the first three quarters from $342,000 during the same period a year ago.

Two agents in Holbrook’s office recently showed 110 homes within six to eight weeks to a couple that was relocating from Texas. The couple ultimately purchased a home in Hopkinton.

But Holbrook is starting to see some improvement in market conditions within Boston and the communities along Route 128, which he hopes will spread to his region.

“Traditionally, when Boston and the 128 belt starts to pick up, it starts to move west,” he said.

Realtor Michael Durkin said one of the biggest factors affecting the market is buyers who are waiting for prices to drop further.

‘Still Making Money’

Many buyers are hesitating because of all the negative news they’re hearing and reading about the housing market, according to local brokers. Homeowners have been slashing asking prices to draw interest, and some have accepted lower offers than they expected.

Durkin, a vice president with Coldwell Banker Residential Brokerage in Northborough, said he recently worked with a couple who purchased a newly constructed home three years ago for $750,000. The couple just accepted an offer in high $600,000s after the home was on the market for six months.

But Durkin pointed out that homeowners who’ve owned their property for many years are still selling for higher than they bought.

Durkin is marketing homes in a Northborough development that was built between 1996 and 2000. Those homes, which originally sold for between $340,000 and $450,000, have been reselling this year for at least $200,000 more.

One home in the development that came on the market in June at $699,000 sold at full asking price within three days, he said. Another home in the development was listed in July and sold within three-and-a-half weeks for about $30,000 below asking price.

“People are still making money,” he said. “But they’re not making as much as they would have made a year ago or three months ago.”

Zide, of ERA Key Realty Services, said buyers who are waiting for a huge price drop will be disappointed.

“I do think it’s going to drop a little more, but if you’re going to sit and wait to gauge the market to find the absolute cheapest price you want, you always lose,” he said.

As for Sullivan, the Framingham resident, she’s done with real estate market for now.

“I don’t think anything’s going to happen [with the market] real soon,” she said.