Sidekick, the way that gun was built its worth ten or twenty times that amount, but its price in today's market is another matter. But, I agree with that offer of $250.00 for a 12 gauge because that's what I would probably offer, maybe go up to $275.00.
I have a 16 gauge Nitro Special, built in 1936 that I paid $400.00 for and put an additional $1,000.00 into it to clean it up. At 6 lbs. 3 oz., and at a total price of $1,400.00 dollars, I still think I stole that thing.
Good luck to you whatever you decide.