I begrudge paying paypal their few percent, not because of the money.
Simply because I dropship and sell a lot via ebay, and you get hit with a listing fee, a final sale fee, then a paypal fee on top, so they triple dip into your money and it irks me. A percentage of every sale I make on ebay goes to the dogs trust charity and sometimes with gift aid calculated this has been more profit than I made. So it's not the money at all. Its just the fact they dip in so many times and you don't realise at first, worse than the tax man!
Anyway paypal doesn't cover intangible products, so theoretically there shouldn't never be a dispute, however a chargeback can still occur and its 50/50 if paypal give you your money back. The only way to be sure if check your seller protection, if its partly covered of fully covered.
I had a recent sale one of my websites for a physical item, a dispute was filed with paypal saying they their account had been hacked so was unauthorised use. Paypal found no evidence of a password attack, the user paid with their debit card and input the correct details first time etc on a card registered months ago was was clearly the user they was just trying to get out of it. So paypal found in my favour within 4-5 hours before I even provided tracking details. The user then went to their bank for a chargeback, and paypal removed the money from my account, which was about 3 weeks later, because I wasn't fully covered.