The PDF version of the 1998-2007 Manhattan Townhouse Report  that I write for Prudential Douglas Elliman  is available for download. I have been writing various reports on the New York region since 1994.
Over 2,500 Manhattan residential townhouse transactions were analyzed over this ten year period. 1, 2 and 3-5 (delivered vacant) family houses comprised the data set.
…The average sales price of a Manhattan townhouse was a record $4,658,155 in 2007, up 14.1% from the prior year record average sales price of $4,082,837. The 2007 record is more than twice, or 116.5% higher than the $2,151,653 average sales price in 1998. Median sales price showed a similar pattern. The median sales price for 2007 was a record $3,125,000, up 15.7% from the prior year record median sales price of $2,700,000. Because the average square footage of townhouses dropped sharply in the past year, the average price per square foot jumped over the same period. Average price per square foot reached a record $1,137 in 2007, up 32.8% above the $856 price per square foot seen in 2006. This indicator is 145% above the $464 average price per square foot in 1998. Other than the decline seen from 2000 to 2001, the price per square foot has been the same or higher than the prior year for the past decade….
Download report: 1998-2007 Manhattan Townhouse Report [pdf]