One variable to look at would be the bulk REO packages that are going around for sale. This would give you an idea of what banks are losing up front. Many of these guys just don’t have the back end support to liquidate the asset so they move it in bulk. Another variable would be the loss mitigation guidelines for individual lenders (countrywide, etc.). This would give you an idea of where and what they are willing to give up as a loss.
Of course, these are only two variables of many. But it would be a good starting point that you could use to adjust *median* prices by. If you are more specific about they area/price range you are looking at I’ll see what I can do about providing some data. I realize some of the information above may be difficult to get.