It isn't.
How much is a 16 gage single barrel shotgun model 350A Revelation
An early model Lefever single-barrel 12-gauge shotgun with a 30-inch plain barrel can be found for sale online for $300. This is the price for one that is in excellent condition.
Numerous companies in many countries have made single shot 12 gauge shotguns.
Less than $100.
$25 to $100, depending on condition.
245
50-100 USD
50-100 USD
$50-$125
In 2012, $70-$200 depending on condition.
It is a single barrel, break-away 12 gauge shotgun.