If you're in contract they usually won't budget for anything since you signed an agreement. If you're lucky they may let you re-up your contract early.. With an early upgrade.. But with way less discount on the phone.
At least that was my experience when I was on AT&T.
When I saw this topic I cracked up laughing. Who in their right mind would trade in any modern day phone for the amazon crap? Really if you plan on doing that or even think you want to then you life under a rock and probably shouldn't have a phone.