Without a detailed description, 20-60 USD
Never heard of a Biretta.
150.00
10-1000 usd
100-400 USD
$1000
10-90 usd
the value of any weapon depends on the model, caliber, overall condition, bore and age.....................
.700 Nitro Express
50-600 USD
a .700 nitro express
You can expect the value to be from $150 - $450 depending on the condition.
Impossible to value with only the serial number and no other details.