The guy I talked to in the store is into black powder a bit. He said it is nice and tight and mechanically functional. He said the timing is right on, it still has good rifling and he wouldn't be scared to shoot it. No way to tell for sure without seeing it. They have it on consignment from a private collector.
Well looks a little rough to be honest. No finish, obviously and pitting everywhere. It would have to be a very good price or best left alone. Of course, we cant all afford the best quality antique guns, and sometimes buying a rough one is a way someone with limited funds can still own one. So, no harm no foul. Even so, if you want a shooter, as long as its tight and safe a rougher one might be better. Cant really say without handling it, especially checking the bore and chambers. Some pitting will be OK, but not if deep.
Does the action work and the cylinder index (When you cock the hammer the cylinder turns, lines up and the cylinder stop clicks in) and lock up? cant see any drag marks on the cylinder, is the barrel - frame tight? I have seen some really wobbly ones. If not, stay away.
I am going to take a stab in the dark on price. I cant imagine he wants less than $500.00 and no more than $1000.00. Maybe $650.00ish? I am out of date on values and not in the US, but wouldnt want to pay too much. Great thing with antiques is if you buy with care you should always be able to get your money back when selling it on.