The highest tier of homes for sale, which has been the last part of the market to feel the effects of the housing recovery, is on the verge of switching from a buyers’ to a sellers’ market for first time in years.

The Institute for Luxury Home Marketing weekly market report today found that homes priced over $500,000 have reached a market action index of 29, one point below the level that typically indicates a sellers’ market because demand is high enough to quickly consume available supply.

The national median price in the ILHMI profile is $1,246,587 for an average asking price of $339 per square foot. The average days on market is 185 and falling. Some 23 percent of the luxury properties in the profile have had some sort of a price decrease while they have been listed, and 14 percent have been relisted.

Every one of ILHM’s 30 markets reports improving conditions. Shortest times on market were reported in Washington (135), Silicon Valley (139), San Francisco (148), Las Vegas (156), San Diego (165), Housont, (170), Austin (178), Atlanta (179), Boston (135) and Ventura (189).

Reports from markets around the nation confirm that sales are strong and inventories are getting tighter in the luxury sector. In the Denver area, buyers purchased up almost 37 percent more luxury single-family homes in February than they did in February 2012, according to a report by independent broker Gary Bauer. Bauer’s report, based on Metrolist data, showed that well-heeled consumers purchased 41 homes that cost at least $1 million last month, compared with 30 in February 2012. In January, 39 luxury homes sold, reported Inside Real Estate News.

The total dollar volume for luxury sales in February rose 30 percent to $57.5 million, compared with $44.25 million a year earlier. The dollar volume last month was up slightly from the $55.7 million in January.