If sending €13.5, the amount that will go to fees is €1.08 and the recipient will receive €12.42. That's 8% going to fees, effectively.
* Using custom fee rate of 5.4% + €0.35
To receive €13.5, a payment of €14.64 should be sent. €1.14 will go to fees. That's 7.79% in fees, effectively.