The PayPal transaction shows the full price, what the seller got. Open
the transaction and look at the details, you will see $XXX in balance or
credit card and $YYY as a coupon.
eBay says it's OK to ask, but really it's not such a great idea, you may
not like what you get if you have a spiteful buyer. I'm running about
35% with buyers not leaving feedback, most of them have never left any
at all. It's voluntary, not one has ...