If you own an iPhone 6s Plus:
Screen (this does not include Touch ID or 3D Touch):
$149
Battery:
$80
Everything else:
$329
I wasn't a big fan of having to pay the additional cost of AppleCare+ with the AUP, but the phone is heavier, there's more components overall and the 'screen' only applies to the glass screen now.
Ok but Applecare you're paying $129 no matter what just to get the service. Then $99 per occurrence of damage. They aren't replacing your screen for free if you pay the $129. So after 1 screen break you're already $100 (6S) or $80 (6S+) in the hole compared to just paying out of warranty.
The odds of an "anything else repair" that Applecare+ wouldn't replace either (like water damage it's not covered) are extremely low. It would need to really get run over by a car or some fluke catastrophic accident.
Battery depends how long you intend to keep your phone. If only 1 year until the iphone 7 then you shouldn't need a battery replaced (a defective battery is covered under the basic warranty) in a year. Apple has publicly said the batteries are good for 300-400 full charge cycles (0-100%)