I think the only way you can see this is to look at all the estates on offer in auction and check each week to see which have sold and which not, and what price they sold for. (This works for those that have buyout and sale price the same- which nearly all do.)
Problem is to know if a house has really been sold or just not been put back into auction by the first owner at the end of the week. Only way to check that seems to be to note seller names in auction and actually go to the house later to check if it has changed. At present houses are being offered for between 4 and 10kish and some are certainly selling at the lower end of that range- dont know about the top end.