They can pay via PayPal, collect, and claim it wasn’t delivered to get the money back.
While I could see how this may work does it actually work or is it just eBay folklore?
It happened to me. Sold a phone, received payment via Paypal, had the money in the bank. Bloke collected it in person.
Next day I had a claim saying the EBay/Paypal account had been hacked so the transaction was fraudulent and would be cancelled. The money was automatically taken back out of my account (~£440).
As I could not prove I had sent the phone to the buyer’s address, I would have lost the money had Paypal not covered it in goodwill solely due to the amount of money I put through them.