It’s a great time to buy, as they love to say in the real estate business.

That is if you can actually find a condo or home worth putting money down on.

While everyone assumes this is a buyer’s market, there just one small problem. It’s not.

There simply are not enough decent and desirable properties on the market for sale. And the few that are worth buying are still overpriced. Until this equation changes, you can forget about any recovery in the residential market.

The problem appears especially acute in Boston’s until–now legendarily resilient downtown condo market, where inventory levels have dropped dramatically, according to one top downtown broker.

Sellers are holding out for something near their dream price, or choosing not to play what appears to be a losing game. It’s a stalemate all right, and, like all stalemates, this one could drag on for years.

The danger is this one could be a repeat of the landmark housing bust of the late 1980s, which took a decade to fully work out.

“People are discouraged by the level of inventory,” John Ford said. “There is lot of pent-up demand.”

The numbers tell the story when it comes to this anemic market.

Listings of condos, from Beacon Hill to the South End, are down roughly 30 percent from the boom.

There were just 1,587 units for sale on the downtown market as of mid-January. That’s down from the more than 2,300 that were on the market at the start of 2006, Ford notes, citing MLS figures.

The numbers are worse when you take into account that condos are sitting on the market nearly twice as long.

Average time on the market has ballooned to 156 today, or nearly four months, up from 84 days back in 2006, Ford said.

That means the few buyers brave enough to put aside worries about layoffs and a global economic downturn wind up seeing the same pool of increasingly stale properties.

“It’s a tough mix for the buyer,” Ford said. “But there is not that much inventory. He is looking at the same inventory over and over again.”

Meanwhile, the owners of the condos that might be worth buying aren’t budging on the prices. And that is not going over well with buyers who start shopping around expecting to find bargains, but instead are confronted with sellers still shooting for boom-time prices.

Ford points to the owner of a two-bedroom penthouse at 18 Garden Street on Beacon Hill, who began trying to sell his unit a year ago. He’s since reduced it to $575,000 from $605,000 after taking it off and putting it back on the market, but won’t go any lower, even at the cost of having to wait it out in order to find a buyer.

“He is not really getting that many offers at all,’’ Ford said. “If he can sell, he will, if he can’t, he will stay there.’’

It’s not just individual owners who are guilty of this. There are a handful of condo towers under construction downtown, including 45 Province near Government Center and the Clarendon by the Hancock Tower. Sales are relatively slow at these high-profile projects as well, but developers have deep-enough pockets to dig in and wait for better times.

Nor is this a downtown phenomenon. Would-be suburban buyers have complained of the same phenomenon. Maybe the owner of that worn and dated cape in Newton isn’t seeking $1 million these days, but $800,000 is still too much.

Yet while falling prices get a lot of bad press – and are none too popular with sellers – you can’t have a recovery without them. In theory, the lower prices will draw out bargain hunters, driving up sales and eventually pushing property values back up again.

But that’s not happening here. Sellers are not budging enough, nor are there enough condos and homes getting put on the market to spark an upward trend in sales. And I am not talking about foreclosures, which are heavily clustered in Boston’s poorest neighborhoods and in hard-hit cities like Brockton and Lawrence. This, for the most part, is a separate market on its own downward trajectory.

But when it comes to the traditional market, whether downtown or in the suburbs, it’s not rocket science why the sellers are either holding out or choosing not to play at all a game that, for now anyway, appears tilted against them. And many simply can’t afford to sell now. Homeowners who bought during the boom entered the housing market at a relatively high level. They paid big money for often modest homes and financed it all with outsized mortgages.

They can drop their prices a bit, but as long as their finances aren’t imploding, there’s a level below which they are not going to go.

What seems to be playing out here is Wellesley College economist and real estate guru Karl Case’s theory on the “stickiness” of home prices during a downturn. Unless they are forced to sell, homeowners will resist selling at lower prices. That means not a swift plunge down the price scale, but rather a slow and agonizing slide.

In a recent academic paper, Case points to two decades of research he and fellow housing expert Bob Shiller has done on the subject. He notes a survey of 254 homeowners in major markets across the country, including Boston, who were asked what they would do if they couldn’t sell. That found that only 5 percent would have “lowered the price until a buyer was found.’’ The rest, 95 percent, would have either taken their property off the market and rented it, kept the price the same and waited it out, or lowered the price step by step.

It’s an analysis that rings true in the real estate trenches as well.

“There is still that tug of war with pricing,’’ notes Ford, the downtown brokerage owner. “If they don’t sell it, they turn around and rent it.’’