Instead of sending the amazon gift card code, I will do this:
http://www.amazon.com/gp/help/customer/display.html/ref=hp_mp3gifts_exchanging_200594010?nodeId=200594010#exchangingOr, I will apply the card to a Anon account and provide you the login details after the 4.5 BTC is received and confirmed.
Both methods provide protection to me against potential scammers claiming that I sent a Invalid Gift Card number. Any Questions feel free to ask.
Maria