My best deal was a trade back in the real early 90s. I was young and broke at a gun show. I seen a older lady sell a dealer a older German made Walther PPK in the factory box with the target used for test firing in the box. It is the gun James Bond used in most of his movies.
Back then a somewhat local dealer was there that sold guns, fishing equipment, and vintage baseball cards. I traded a 1966 Topps Sandy Koufax in NrMint condition for a new Smith & Wesson 38. I then traded the S&W even up for the Walther PPK I wanted from the other gun dealer.
The dealer with the Walther didn't look close to see it was a German made gun and not the American version. In card terms I traded a common T206 even up for a T206 Red Cobb in the same condition.