0-multiple thousands of USD, depending on who made it and its condition.
40-140 dollars depending on condition and a good bore.
The value of a Nitro Marvel 1886 16 gauge shot gun in working condition is between $199 and $165. As a parts gun only it is valued at $39.
50-100 USD
$20 US if your lucky
100 USD
50-500 usd
What is the value of belknap model b63b 16 gauge shotgun and who made it.
10-100 USd
100-300 USD
10-1000 USD and up depending on specifics
Blue Book of Gun Values is a good place to start.
50-100 or so