Edited my post above.
Avoid paypal at all costs when you are dealing with bitcoin.
let me quote their terms and conditions:
You may not use the PayPal service for activities that:
-snip-
3. relate to transactions that -snip-
involve currency exchanges or check cashing businesses
-snip-
Don't think that part of T&C was meant to relate to cryptos. It just doesn't make sense why ebay (who owns paypal) would allow trading BTC and even made a separate category and paypal would disallow it.
I bought my first BTC on ebayUK (around Nov 2013) on both auction and buy it now format (allowed back then) and had no issues. Then again, I recall a story about someone's funds being frozen due to selling BTC mining hardware... just weird.
OK, what if a buyer sends funds to the seller but not as a payment for anything, just person A sends to person B (as a gift). Is it still a risk from seller's perspective? Can it be reversed?