What model????
Winchester made the Sears Model 200.
Depends on model and condition. Typically $100-$150.
$125-$175.
High Standard. http://www.histandard.info/PDF/Sears%20Shotguns.pdf
Sears Slug Model 446.511761 is a Mossberg 500. All parts interchange.
I believe that your Sears shotgun is a Winchester model 37A shotgun that was made for Sears Roebuck And Co,.
Winchester
about $100
numrich gun parst e-gunparts.com this is a complet book on parts and prices.
about $100
The value of a Sears Roebuck 12-gauge 101.100A shotgun is around $100. This depends on the the condition of the firearm.
The Sears Roebuck Model 300 12-gauge shotgun with serial number 273521160 was manufactured in 1964. This shotgun was produced by the High Standard Manufacturing Company for Sears, Roebuck and Co. It is part of a series of firearms sold under the Sears brand during that era.