I have a similar concern although the mileague is far from reaching 80K miles yet! A quote from a local (Canadian) dealer is: pump $CDN 162. and labor 1.5 hrs, or about $CDN 130. Sounds reasonable to me.
I did point the service advisor to the CEG link on this problem; he suggested the pump to replace, not just the impeller.
I appreciate the extra info on the stainless steel cone that is not part of the pump, and that needs to check for looseness.
