Sorry but I cannot see any profit margin here ....
e.g. you are selling $25 itunes at €15 .....
they are sold on eBay for around €22
so if I sell at €20, my fees would be €3.33, so my total cost = €18.33
so my "profit" would be €1.70????
even if I sell at €15 on eBay, fees would be €2,80