As with O2 there, so with AT&T here or more accurately with myself. Give the phone gratis and I'd ship it back out of pocket.
It still begs the question, why the exclusive arrangements? I actually like the idea of the Fire Phone and I'm not committed at all to Amazon. (Newegg, &c, yeah) The instant lookups would suit the extended families just fine. Betcha I'd want a commission on each additional phone. No AT&T, period, from all of us to all of Amazon. I conducted a survey.