I am not sure that I have seen a Mullin gun with the full name of Patrick Mullin that wasn't a muzzle loader. These guns are not common. All had the highest degree of finish. Mullin did not like engraving, so except for some screws or tiny areas, his guns were unengraved. If memory serves me correctly, his guns were priced in the $200-300 range. Certainly a limited market.

http://www.bakercollectors.com/