For the fourth consecutive year, Forbes.com has compiled a list of the year’s residential real estate deals. In the face of a general housing market slowdown, 2006 was a banner year for those that deal in high-end homes. The average price of a home on the list was $40 million, up more than 10% from 2005’s $36 million average, and more than 55% from the 2003 average. It should come as no surprise that the priciest properties were ...