When it comes to Manhattan real estate, timing is everything.

If you bought an apartment in the borough a decade ago, you should be very happy indeed: The average sales price in Manhattan in 2011 of $1,426,912 is a whopping 80% higher than the average in 2002, according to a new report from Prudential Douglas Elliman.

“The big message is: steady, steady, steady, safe, safe safe,” said Steven James, president of the Manhattan brokerage firm for Prudential Douglas Elliman.

Of course, if you purchased at the peak of the market in 2008, when the average price for an apartment was $1,591, 823, you’re not as lucky. Prices are off by about 10%.

Even so, the report shows just how resilient Manhattan has been compared to the rest of the country, where prices are 30% below the peak reached in 2006.

“While the national market is still declining, Manhattan has been stable for two-and-a-half years,” said Jonathan Miller, CEO of appraisal firm Miller Samuel, which compiled the Prudential Douglas Elliman Report.

In general, the more affluent an area, the more its real estate has held up, Miller said. Manhattan has also benefitted from limited supply and active foreign buyers, who have helped spur healthy sales at the high end.

In the latter part of the decade, the borough saw an uptick in sales among three- to four-bedroom apartments. Some have gone for dizzying prices.

Last year witnessed the record breaking sale of a $48 million condo at the Plaza Hotel to Russian composer Igor Krutoy. That was topped by Sandy Weill signing a contract for the sale of his 15 Central Park West palace for $88 million to Russian fertilizer mogul Dmitry Rybolovlev.

Another sign of Manhattan’s strength: inventory has remained steady over the last decade.

“Inventory is the shocker,” James said.

It hasn’t changed. Inventory went through the roof in 1980s. That never occurred in the last decade, even when Lehman fell.

“People feel very good about wanting to live in the city,” he added. “Quality of the life in the city is at its best. New Yorkers want to be here.”