IPhone 5s for iPhone 6 cost?

Ok so I have the iPhone 5s right now and I want to buy the iPhone 6. So how much would I get from the iPhone 5s and how much do I need to put on top of that for the iPhone 6. And yes I want it with a contract if that helps.

This strategy changes often, since the companies are in competition but this is general advice. Look into selling your 5s. We got the best prices from Amazon, because they pay you in Amazon bucks - not cash - so you get MORE, since you are going to spend it on Amazon eventually. Then - when your contract is UP (not before! They tell you that you *eligible for an upgrade* - yeah, that means you are eligible to get screwed on the price!) BUY an iPhone 6. If I were you, I would wait until the iPhone 7 comes out - THEN buy a 6 - the prices will drop on 6 while all the idiots run to get the 7. PAY for the phone as you sign up for a 2-year contract. Do NOT NOT NOT take the plan where they add onto your phone bill each month to pay for the phone - and have the NERVE to tell you it was FREE - when you are going to pay Way more with the monthly add-on, than if you paid up front. Loose figures - you pay $200 up front ( might be less when 7 comes out, if you get the 6). Add-on plan - you pay maybe $25 a month for the 24 months of your new contract. That comes to $600! I hope you can follow the math here - I'm a retired teacher, and have explained this to TONS of people - and many just look at me and say "But THIS way, I get it free - with just a little bit extra each month… " STUPID! So - YOU be *smart* about this - check online about price, and KEEP checking -and wait until at LEAST September when the new 7 comes out, OR you plan is up - which ever is LATER.