I would prefer that someone round up all those guys who ruined modified model 12s with polychokes (that they would then set to modified) and make them shoot mossbergs.
To answer your question, it's probably a fair deal, you didn't tell us the condition of the gun or any other factors about it. The polychoke cannot be removed other than cutting the barrel, and then you have no choke at all. I have no idea what the cost of a 16ga barrel would be. The 16s are worth more than the 12s, and you don't see a lot of spare barrels in good condition. Then the ones you see are blown out, full choke, or have a polychoke of their own.
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