Seems to be more and more FB scams from people pulling pics from other vehicles and listing them under market value, sometimes way under. I always click to see how long they have been on FB and how many friends they have and would always do the deal in person, clean title in hand if any questions. I'm not saying this is a scam, it's just running rampant on FB Marketplace and it's a shame as it didn't start out that way. It was a better option than CL, but now, not so much, maybe worse. Buyer beware always...
In this case, the "no friends" to me is a big tell that this may not be legit.