I need some experienced shotgun shooters or gun enthusiasts to help me assess value to a shotgun I got in a partial trade. It is a Mossberg 500A bought new in 2000. It has 2 barrels, a 28" vented rib shot barrel (2 /34 and 3) with Accu-choke and a 24" Rifle slug barrel with rifle sights (not rifle but smooth). Both barrels are ported. There is a small amount of rust on the shot barrel and magazine tube. The stock is in good shape and the handguard has slight crack(in pictures). What would you value this at? What would be cost efficient to this shotgun for sale? I am looking to get the most out of a sale with the least amount put into the shotgun. Thanks ahead of the time for the help.