Depends on model and condition- not enough info to answer.
The current Barrett Firearms does not make a double shotgun. Exactly how is your gun marked?
All right...what about it? There is no question there. how old is it
try e-gunparts.com
50-100 USD or so
Many companies have made firearms for the NWTF.
$100 to $250, depending on condition.
"The Berkshire" by Meridan Firearms "Berkshire No. 3000" by Crescent Firearms Contrary to popular belief, not the same company.
70-100 years
1890's.
contact Rick Cutter @ maricopafirearms.com
Made by Meriden for Sears. 50-100 USD
Check out gunshop.com,they got Lots of info on dbl barrel shotguns.