Quoted from cosmokramer:
Everybody bitched when e bay tacked on 10% fees to shipping costs as well as the cost of the item. What were they supposed to do, let everybody sell a $300 item for $18 and charge $282 for shipping to avoid fees?
Ugh, I was ticked off when they did that with no notice. I called them because money was disappearing and there was no explaination as to where it went. I was probably on the phone for about 2 hours since nobody was able to tell me what was happening at first.
As for an alternative payment processor, I've heard of some people using square for in-person purchases. There are a bunch of other alternatives too, so taking credit card payments and whatnot isn't a problem.
However, finding an alternative for person-to-person transactions is tough. Almost everyone has paypal. It's basically a standard. If you go with another service, it's usually safe to assume other people don't use it. Google wallet is one service that can do free person-to-person transactions, but I can't think of anyone who actually uses it.