This from Paypal website:
Can I surcharge PayPal payments?
Yes. To ensure merchants are given a reasonable opportunity to recover the costs of accepting payments online, we’ve aligned with the Reserve Bank of Australia’s (RBA) new card scheme surcharging standard.
If you choose to, you can surcharge up to the average fee you’re charged per transaction by PayPal over a 12 month period. However, we don’t recommend you do surcharge your customers. Adding a surcharge can significantly increase your abandonment rates and, in turn, your ability to grow your online business.
Any surcharge you apply may only be expressed as a percentage of the sale total, not a fixed dollar amount.