Forums / Gun Discussion / Belgium Browning

Hey Yall i was wondering if someone could help me. I received a Belgium Browning superposed lightning over and under from my grandpa a few weeks ago. It was his trap gun and has only about a box of ammo through it. i went to brownings web site and looked up the serial number and it was dated before WWII. can anyone tell me the value of the gun. i want to get it insured and when i took it to a dealer he told me it was worth 800.00 then immediately asked if i wanted to sell it. I have been around guns my whole life and i know for a fact he was trying to rob me. if anyone can give me any info i would be appreciated