maybe split the difference between...
...what paypal would have charged & the bank fees?
or just ask the buyer to cover.
Whatever you are both happy with to see the deal go sweetly.
Very best.
further info...
the only possible cost for you will be a fee to receive the cash, BUT you can get the buyer to cover these fees by getting them to advise their bank when making the transfer. Usually less than a tenner but still worth knowing about.
The BIC/IBAN numbers will be at the top of...