It might well be a scammer. Might also just be someone's idea of fun for the boring life they lead. Seems that more and more I'm hearing the same type things going on with FB marketplace that has been going on with Craigslist for most all of this century if not prior also. Craigslist did provide a way to have conversations about the item for sale without having to disclose phone number or email. I hope FB marketplace does too.
Lately for things that are too big to go in the mail or package delivery, I'm happy just sending them to the scrapyard to be recycled if there are no friends that want it.