Always a good idea to nix a sale to someone who just turns you off in how he acts, speaks, dresses, smells (like marijuana, maybe) or just generally looks (like Charles Manson, maybe). You have to protect yourself if the buyer turns-out to be someone who should not have had a gun. Even if all you did was sell him a gun in good faith, it puts you into the case if the law ever gets involved because the gun was recovered after some sort of crime was committed with it. The survivors of the victim will certainly sue you just because you were the source for the firearm he used in the crime. Makes no difference to their lawyers that you did not know the buyer was out on parole for domestic violence with the subsequent murder of his ex-wife.I've also turned-down purchases and/or sales with people who just "didn't seem right!"
I'm a bit skittish about pawn shops, but not private parties!
I never saw any issue of Backpage. It may have been available in Reno, but not in the tiny town where I live. I've never bought a gun from another citizen. I always figger-out what I want, then go look for it and buy it new. I have bought one from a pawnshop. It was in really nice condition and at a good price, so I melted and paid the money. I would suspect that when you buy privately, you have no recourse if the thing has problems. You bought it, you own it and it's up to you to pay the 'smith to have it fixed. I'd have to ask why the seller wants to unload it. A good gun is always worth keeping, no matter how infrequently it's fired. Maybe that $200 stainless Kimber has expensive problems?