It's new to me with gun auctions. I bought and sold through both Rock Island and James Julia and never paid sales tax. IF I ever bid on an auction rifle again, I have to factor in the sales tax along with the buyers premium, so obviously will bid less based on the value of the rifle to me than I would have. Morphy's buyers fee is 20% so there I would be paying a total of 27.25%! The seller is taking it on the chin as he also will be paying a sellers fee!