I got offered this pistol in trade today, and it seems to be in pretty good shape. I know some of these are collectible, but not much more than that. Can anyone throw a reliable ballpark value on it so I know kinda what I might be getting into? It is a Smith and Wesson 27-1 .357 magnum with an 8 5/8" barrel. Comes with Original wooden presentation case. He says he is the original owner, has the original receipt and it has less than 200 rounds through it. Thanks. Semper Fidelis.