I don't know if there is anyway around this since I am assuming the software simply pulls the information from the auction house database but I just noticed that Goodwin auction I won for $100 (
http://www.goodwinandco.com/LotDetai...&seo=1895-Mayo) is listed with the buyer's premium here:
http://www.cardtarget.com/cgi-bin/gm...037&grade=auth.
Obviously this inflates the pricing data sets and this is how Goodwin is reporting it.