So, a dude's out playing around with his metal detector, and it goes berserk.
He starts digging and pulls something that looks to be a rusted, dirt-encrusted revolver from the ground.
After a bunch of cleaning and scrubbing, however, it turns out to be an FIE Tiger, which is not actually a gun, but rather a gun-like object.
Assuming it was in 100% condition, the Tiger would be worth somewhat less than a hundred bucks. As it is, I wouldn't let him put it back in the hole unless he gave me a twenty.