lcpiper, I didn't say it should be illegal to have strangers come to your home to view and possibly purchase weapons, nor do I think it should be illegal.
I just think it is stupid, because you don't know who you are inviting to your home; you are telling that person "This is where I keep guns."
As you implied (correction, as you explicitly posited) earlier, what if you abort the sale, and he now decides to burglarize your home for your firearms? It was you who suggested the possibility, after all, so I don't see why you are now saying it is no big deal simply because you wouldn't abort the sale.
Whether you meet at an FFL, or just some convenient neutral ground, I really don't care. For that matter, I really don't care if you invite potential burglars and assailants into your home. It's your home, your stuff, your risk.
But I think it is unwise. I would opt for an FFL's location, if concerned about the buyer; I would opt for a gun shop parking lot or similar, if I weren't concerned but did not know the guy. (And I have done exactly that with a guy who worked for another department within a large command; I didn't know the guy, but I did know from the method through which he contacted me that he held at least a Secret clearance, so I was comfortable that he was not prohibited. Still, why invite an unknown to my home? We met in a gun shop parking lot.)