Trying to sell low value item on Facebook marketplace, are 'buyers' trying to scam me?

That’s a cracker! These people are insane. My uncle bought a 1950s house that had a prefab concrete garage freestanding on the  side, long enough to hold three cars parked end to end, and would have taken hours to smash up and many, many skips to remove. So he listed it for free, buyer must dismantle and take away, obviously. First taker didn’t turn up, so a few days later a farmer got in touch, came down within an hour with a flat bed lorry and five blokes, they had it removed within two hours. Gave my auntie a big basket of goodies from the farm shop, and told my uncle to come up at Christmas because there was a fridge full of meat with his name on it reserved. So - and it’s somehow always two weeks later isn’t it - the first lady eventually arrived to collect and was irate, telling my uncle the farmer would have to disassemble it because it ‘legally belonged to her’. Btw she’d arrived to collect it in a small VW car, with just her primary school aged daughter there to help