i had an itunes gift card but the $ ran out. i just got an american express card, can i buy a gift card with the american express card? i found a thing where you can email an itunes card so i think im gunna email a card to myself, however i don't want it to bill the billing address so i put in the American express gift card number... after ( before i click buy) it said " You're credit card will be charged $10" are they referring to my gift card? b/c i entered the gift card number into the american express credit card place...?