**correction**

As far as fees on postage goes, this was done to death many years ago.  My own view is that eBay wanted more sellers to have ‘free postage’ on their listings.  However, if a seller included the postage into the price of their item they paid fees on that postage, but if they charged a postage amount they paid no fee on that postage.  Their solution was to charge fees on the whole transaction.  This also stopped sellers getting away with charging pittance for their item and inflated amounts on postage.