The median home price in Manhattan slipped below $900,000 in the third quarter of this year, compared to the same period in 2011, according to the latest analysis by appraiser Jonathan Miller, who reports on the housing market for Prudential Douglas Elliman.

The median home price in Manhattan slipped below $900,000 in the third quarter of this year, compared to the same period in 2011, according to the latest analysis by appraiser Jonathan Miller, who reports on the housing market for Prudential Douglas Elliman.

Miller said that although most price indices are down slightly, the real surprise is a sharp drop in the number of homes for sale.

“Inventory has fallen 24.3 percent year over year to the lowest level in seven and a half years,” he said. “It's getting to the point where over the next couple quarters we may very well see some sort of price appreciation.”

Miller believes some would-be sellers are spooked by persistent high unemployment and turbulence in the world economy, and only a significant rise in prices will move them to act.

He says despite a number of eye-popping prices for high end homes, fairly few mid-market units are changing hands.

Last month, the sale of a $90 million penthouse apartment in a building still under construction known as One57 caused rampant media speculation about the buyer. The identity of the purchaser is still unknown.