Hello! My friend Ryusenka, recently told me that it's against Paypal's TOS to charge a customer the Paypal fees. If you take commissions be careful about asking the customer to cover PayPal fees! You could lose access or have your account suspended! Ouch!
The TOS specifically states:
"4.6 No Surcharges. You agree that you will not impose a surcharge or any other fee for accepting PayPal as a payment method. You may charge a handling fee in connection with the sale of goods or services as long as the handling fee does not operate as a surcharge and is not higher than the handling fee you charge for non-PayPal transactions."
You can avoid that by including the cost of the fee into the overall price.
Stay safe everyone!
Edit: Explanation on the handling fee... For example, if you sell necklaces at a convention for $5.12 with credit card, you should not sell it for $5.45 on PayPal. Instead, what you can do is charge $5.50 for your necklaces, and say the 50 cents is a handling fee. The reason for this is Paypal doesn't want to look bad for having fees, so they make it against their policy to make the buyers pay for the surcharge. Just don't call it a PayPal fee or associate it with PayPal, or they might deck you.
A handling fee that doesn't exceed your other forms of collecting payment is perfectly acceptable if you need the customers to cover the costs of the fees.