Options in "view pricing" in store app

So I've gone through the pre-order steps by choosing the phone, size, etc. I chose replace this phone on my at&t account. The next step give the purchase options, Pay in full or AT&T next. Just curious why the Apple payment plan isn't included in the options. Just strange. Has anyone else seen it there?

Not sure if any of this matters anyway. I did the "get ready to pre-order" thing and at the end of that all it says is that I'm eligible for AT&T next.