Editor's note: This report is based on Realtor.com's October 2012 Real Estate Trend Data Report. The report covers 146 U.S. metros, and includes single-family homes, condos, townhomes and co-ops. For-sale inventory hovered near a five-year low, but median list prices slipped in October back to the same level as a year ago, Realtor.com reported today. Inventory stood at 1.76 million units at the end of last month, down 17 percent from a year ago and 40 percent below a September 2007 peak of 3.1 million.Despite the scarcity of listings, median list prices slipped 0.83 percent from September to October, to $189,900 on average -- the third straight month-to-month decline. Median age of inventory at 97 days was down 11.81 percent from a year ago, but demand still seemed to be slipping...