How much does it cost to trade in iPhone 6 16gb for 6s 64gb?

I have AT&T and my iPhone 6 16gb is to small for storage and I need something with more gb since I have a lot of songs and apps. I have to keep deleting apps and it's annoying. Do I have to pay another $800 or do I get a discount with my carrier?

It depends. Is the 16 gig phone paid off and are you due for an upgrade? If it isn't paid off, you get screwed.

If it's paid of, and you want to get ripped off, trade it in. You might get $100 for it. If you want to get the most you can for it, try swappa.com. I got $275 for a phone that ATT would have given me $100 for.

If your phone is paid off, you can get a 6S for about $25 a month.