I attended a gun show in Ephrata last week...While the gun prices were sky high, I did manage to bid on a few box lots of shotgun ammo and some gear...One box I won had an assortment of turkey shells and some turkey calls..One of the calls was in it's original box along with all of the brochures, etc...…...I put these pictures up on a "call collector site" to find out some history on this call....Everyone seemed to go nuts over this, calling it the "find of a lifetime".....Until that day I had never heard of Neil Cost, but I guess he was some turkey call "pioneer".
Google old gobbler turkey hunting forum.
There you may just find a call maker/ call collector forum to get some idea of it's value.
I don't collect them, but I've definitely heard of Neil Cost calls. Many call makers emulate his designs to this day. I believe there is even a call making award named in his honor.
Nice. It couldn't have happened to a better guy. I would think there is definitely a market for that call with all of the original paperwork and original box. Old Gobbler is a good place to start if you do indeed want to get an approximate value and they also have a classified section if you decide you want to sell it.