Know what you are buying. example, A couple of years ago I ran into a nice old Charlin, a double barrel sliding breech shotgun similar to a Darne. The big difference is the locking system, the Darne being much stronger, and the Charlin having the sliding breech acutally running on hidden ball bearings so it is super smoothe and very tightly fitted, but still not worth as much as a comparable Darne. Anyway they were calling it a Darne and asking $3600, I looked a couple of times, took a card and walked away. I did a bit of research, contacted the dealer who had the gun on consignment and educated him a bit about it and got it for a little less than half the asking price. It paid to wait, research the gun then make an appropriate offer.