That's a good a deal, though I think there is a time limit to use the
Amazon promotional credit. I don't think you will find a better deal as long as you can use the Amazon credit.
I want to give you a warning about using gift cards to purchase AppleCare. Do not redeem the gift cards to add to your Apple balance. You can purchase AppleCare with Apple gift cards, but you have to go to an Apple Store, and you need to leave the balance on the gift cards. You cannot purchase AppleCare from your Apple balance, and you cannot purchase AppleCare from home with a gift card. I think there is also no way to apply a discount, like a student discount, when purchasing AppleCare with gift cards.
It's a weird quirk, and it comes up from time to time. Here's a recent thread on reddit. The thread implies that this is something new that began this summer, but it's been this way for years.