PayPal's refund policy does leave a lot to be desired yes
And that's a valid concern. People are abusing it a lot and PayPal's staff is less than competent, especially when it comes to digital goods/services.
And get charged more fees lol, percentages have the habit of scaling
You know what the fees are, so you can adjust the price accordingly in order to get the exact amount you want.
There must be reason other than fees, probably PayPal's refund policy