We would need to know the model number and other specifications to possibly answer your question. As with any firearm, it is not possible to accurately appraise a gun without seeing it. Recommend that you see a local gun dealer for an appraisal. You can also do your own investigation by looking at other models being sold that are in the same condition as yours. Try the gunbroker.com or a periodical called "The Gun List" You can also reference the Blue Book of Gun Values which can be purchased on line at various retailers.
10-800 usd
50-5000 usd
50-300 usd
Impossible to answer without a detailed description of the condition.
50-475 usd
value of belgium browning 25 auto baby blued with walnut grips
Which model?
75-450 or so
50-350 usd
It is not possible to value a weapon with just the serial number.
made in 1976
$400-$500 in excellent condition.