It seems like the way to go with this is...
BuySEND a $10 Gyft card with the ePizza money on Account #1.
Then sign up with another e-mail address to make Account #2.
Then use the $10 Gyft card + the $5 off $50 Promo Code to buy a $50 Amazon card (for $35 out of pocket) on Account #2?
Is that the idea? I don't know if I should go through all of this to save $5 or if it'll actually work.
EDIT: Well, I was the guinea pig here. I "bought" the $10 Gyft card, but it adds it to Account #1's balance, so you can't use it on Account #2 with the promo code. Ah well. I think the way to do it would be to choose to SEND a Gyft $10 card to your other e-mail address if you want to try this.
Did this and it worked for me and now I have a $50 amazon gift card to regift for Christmas