@Chump Thumper Gold is a pretty popular one I would say. But Full Titled Of Exceptional Quality Plate is all one of the more expensive types. I would say 5-10m per piece. I can't imagine it going for much over 10. And that would only be in a auction type scenario. Now if you had a full set then it would probably fetch more per piece as people want to be able to display a full set. Hope that helps.
I do however need that piece and therefore would be willing to pay the top end of that price range. Let me know if you want to sell it. Thanks