So I responded to an ad on face book for a Mooney M20K. Pics looked good, price was a bit lower than market, not crazy low, but enough to make my spidey-sense start to tingle. Anyway, attached is the discussion in had with the seller (scammer). I got a good laugh at least.
1800 pounds is likely the empty weight of the aircraft. Never ascribe to scamming that which can be explained by incompetence or you may never find a plane to buy.
There's a fair number of scammers on TAP and an infinite number of scammers on FB.
It's even worse if you consider airplane accessories, like headsets, sentry/stratus, etc. I wouldn't buy any accessory online unless it was from a very long tenured member of PoA/EBay/etc.
But the good news is scammers are turds that are usually easy to spot. Since they typically have the IQ of a potato they say things like Mooneys can take 1800lbs of LL.
Hope you reported the listing so a more trusting individual doesn't fall prey