When in doubt...I don't....I have turned down sales based on a "bad vibe"......
"WTF do you mean you won't sell me the gun because of a "bad vibe"?"
"Bad vibe"...It's 70's talk for GTF out of my shop? Do you understand now?"
I would think the 'bad vibe' sales method would be risky in this age of the ever-proliferating "protected classes." Seller says 'bad vibe,' and buyer says 'I'm a victim of [choose one]ism."