$10 to $10,000. Depends on which gun- and there are thousands of different semi-autos.
0-60 usd
25-125 USD or so
50-100 USD
Blue Book of Gun Values
Impossible to value with only the serial number and no other details.
Yes, to some extent.
50-500 usd
Impossible to value with only the serial number and no other details.
Value of any firearm is based on the current condition of that particular firearm.
50-1000 or more depending on the specifics.
100-300 USD
Depending on EXACTLY what you have; 100-1000 USD