As the rest of the housing market struggles, the very high end is thriving. The Dallas-based Institute for Luxury Home Marketing estimates that home sales at the $5 million-plus price range rose 11% in 2006, compared to a 8.4% decline in overall housing market sales. Between 1999 and 2005, the institute says, sales of homes for more than $1 million skyrocketed over 500%. Today, there are seven homes on the market priced at $100 million or more. In 2005, there was just one.