Figuring Fee Amount

[Gigibuys]

I sold an item for $89.90 plus 4.05 shipping. Tax was $5.64 so the buyer paid a total of 99.59 through paypal. It was a U.S. to U.S. transaction.

PayPal charged a fee of $8.83.

Does the PayPal fee include collection and withholding of the tax? Or is there some other explanation for such a high fee?

Thank you for helping me to figure this out. Be healthy and stay well!