If sent by Goods and Services then yes, they take a cut.
Always calculate it in advance from their published figures on how much they take, or use something like:
http://finalfeecalc.co.uk/paypal-fee-calculator-uk/
This is why some sales listings will insist on payment via Gift, but this leaves the buyer with no PayPal protection if the item doesn't arrive/they need to get a refund. But equally, a gift payment can be reversed far more easily by the buyer, meaning the seller equally has no protection even if they can provide evidence they sent the item and the buyer received it.
Stick to bank transfers as a seller, and PayPal Goods and Services as a buyer!