EBay insists that you must accept PayPal when an item collected, even though they're well aware that this exposes the seller to an easy and well known fraud.
There are two risks, actually.
The first is that eBay itself now makes items paid by PayPal and collected in person eligible for its money back guarantee. As always, the problem is that eBay automatically takes the buyer's word for faults, so they can invent almost any fault to return it. It's probable, although still not entirely clear, that eBay may also require the seller to provide a prepaid return label (which for heavy items may cost more than the price it sold for!).
The second risk is that the buyer can engineer a chargeback. Without proof of postal delivery there is no defence against this, and the buyer gets to keep the item and a full refund. The seller even has to pay Paypal's admin charges for the repayment. This scam has even been exposed in the national press, but eBay has never seemed to care about the seller.
For items of moderate to low value, such as you've sold, you should be pretty safe if you have a witness present, ask for evidence of ID, get the buyer to sign a collection receipt, note their vehicle registration and take a photo of them loading the item. Having this amount of evidence should deter most opportunist thieves from risking a police investigation for a chargeback fraud.
