Requiring someone to use a credit card or debit card is asinine. So they want to limit sales to two per person. They can just as easily use your ID. To the person who said they need to access to multiple states ID databases. No they don't they can just assign a number to that ID for their internal purposes.
Problem solved now people can pay with cash, gift cards what ever. I bet if another company were doing this you people would not be okay with it but because it is Apple it is okay.
The people selling them on ebay are probably big operations that do have multiple credit cards or they pay people to buy them for them. So this policy does nothing but hurt the person who isn't trying to resale.
To the original poster, I hope it works out for you and you get to use your gift card to purchase it.
Thank you. I'm sure it will work out because American Express ALWAYS sides with it's customers and will do what it needs to in order to resolve the situation. It is in fact against the merchant agreement that Apple signed with Amex and most likely it's other credit card processors.