I am sorry to poop on this chart but it is meaningless to me.
How does the discount calculation get done for a price range? Do they use the lowest or the highest value? What if the sale is a short sale? What if the sale had an agreed to price but then the price was modified because the home did not appraise? What about concessions that were made for repairs or other credits back?
Also in reference to what Dave wrote, a measure of sellers delusion would be more useful or to put it in more practical terms a comparison of what zips have fallen more verses others is most important.
I believe Esmith has that CS analysis based on zip codes on his website.