Because you get the first 50 for free so they charge higher for listings over the 50. In the past, sellers were charged an insertion fee based on the starting price. Other than on special occaisions, there were no free listings. To make up the revenue they lose by giving 50 for free, they are charging higher insertion fees, higher FVF and a FVF on shipping (the shipping is because of too many sellers were listing items for a low price but with excessive shipping in ordre to circumvent the insertion and FVF).
