i don't know either, but it seems to me that this is an ebay transaction, and not an in-person transaction, regardless of the delivery/pickup procedure. the item was listed on ebay and is purchased through ebay; ergo, an ebay transaction. not craigslist, f.b. marketplace, garage sale, or some other in-hand fee-less transaction--ebay will collect their fees (and required taxes) on this sale, so their services are provided.
i expect there is some fine print somewhere...
I haven't done eBay in awhile, but payments used to be 100% through PayPal as eBay had purchased PayPal many years ago.