http://answercenter.ebay.com/question/Paypal/Pays-Paypal-Fees/900324073

The seller DOES NOT offer Paypal as a payment option.

Therefore any Paypal payment will be made outside of ebay checkout.

German sellers CAN surcharge for Paypal.

See section 4.5 of the German Paypal UA.

Since the buyer wants to pay by a method that is not part of the listing and they want the seller to accept their payment, they might want to pay the surcharge.