If you bought a Manhattan townhouse a 10 years ago, congratulations! That was a fabulous decision. A new report from Elliman shows that the average price of Manhattan townhouses has increased more than 51 percent since 2005, while the median price is up 30 percent (price per square foot is up a whopping 90 percent). The average price is now $5,888,837, and the median price is $4.1 million. Report preparer and appraiser Jonathan Miller points out that townhouses represent just 2.5 percent of the market. "It is really a luxury niche market," he says. Townhouses "saw larger gains in all price indicators" over the last decade than the entire apartment market.