In years gone by, ebay only charged a final value fee on the end price of the item. What ended up happening too often was sellers were listing items for a really low price like 99 cents but charging the price they wanted for the item as shipping so they would not have to pay the higher fee.
I have in seen sellers list 99 cents for athletic shoes but charge $150 and up for shipping so they would not pay a fee on the $150 shipping. I once seen a set of listed for really cheap but with $400 shipping. It was called fee circumvention.
Well, ebay decided that it would charge the fee on the total sale and not just the item price thanks to the few selles who abused the system.
Non paying buyers deserve unpaid item strikes.