eBay's fee scales are clearly set out up front. If you don't like them, don't use eBay, simple.
I also prefer PayPal. I have always had good service and no issues. On one occasion, they refunded me most of the money I paid for software which turned out to be pirated.
Sellers charging excessive postage to circumvent the fees are breaking the rules - also stated up front. If you're affected by this, complain to eBay and they will pull the auction.
Some people say eBay don't give a damn as long as they get their cut. My experience suggests eBay are pretty strict and getting stricter all the time. Remember all that pirated software?...you don't see much these days. Spot an obviously dodgy car for sale and it will soon get pulled.
There are almost bound to be problems now and then. Name one business that doesn't have them. Considering the colossal scale of eBay, it never fails to amaze me how well it all works.
JaX
