But they seem so genuine…
Details vary from scam to scam, but typically fraudsters will pose as interstate or overseas buyers keen to buy advertised items sight unseen. They are unlikely to negotiate on price and may even offer to pay more than asking price.
Explanations for overpayment range from banking errors to cheques being from a previous sale that fell through. The buyer may even claim that the ‘extra’ money is for ‘shipping expenses’, ‘insurance’, ‘customs duty’ or ‘agent’s fees’.
The catch is the seller has to refund the excess amount to the buyer, usually through an online money transfer service such as Western Union. The seller will later find they were provided with a false receipt for funds that were never transferred or that the cheque they were provided with was false, but not before they parted with the ‘extra’ money and possibly the item for sale too.