I actually played with one of these scammers for a while, to the point of receiving a fake cashier’s check. In their case it was not for the full amount, although they said they’d be sending extra.
I had a fun email sparring match with them for a while and when they decided to get threatening, I mentioned that they needed to give me complete FFL information since they were trying to buy some guns that I had listed on a local community buy/sell site, and they wanted me to ship them out of state. After all, I noted, I’m sure they wanted to comply with all applicable federal laws. Never heard a peep from ’em after that.
Cf