This question needs to be narrowed down to Model, make, guage or caliber and also condition. There are dozens of Belgian made models and values ranging from $200 to over $30,000.
Impossible to value with just a serial number.
Please state the model.
100-2000 usd
50-500 USD or so
Fiscal? A few dollars, pounds
500 USD
$450-$750
The exact value of a Browning 1973 U73 22 pistol made in Belgian is actually dependent on a number of factors. Most importantly, the condition of the pistol.
Value depends on condition and which version you have. Use the link below to find the value
$350-$650.
Impossible to answer without knowing which model.
50-600 usd