When you pay with paypal you pay a conversion fee as you do with whichever financial institution does your conversion.
Paypal builds this conversion fee into the rate you are charged.
If your bank does the conversion you pay the amount of the invoice and later you are charged the conversion fee.
With paypal there is one payment and that is the end of it.
Over many years I have found that paypal fee is usually slightly better than my bank but you are free to have your bank do the conversion if you want to.
