How much would it cost to upgrade an iPhone 4S to iphone 5c?

I have an iPhone 4S but rumours say that the iPhone 4S Won't last long on ios7.So I would need a new iphone I'd like the new 5c or 5s where is the cheapest to upgrade carphone warehouse or phones 4 you or O2

Won't last long on ios7, what are you on about? It can have ios7 loaded on to it and will run that for ever and a day, it may not be capable of having some of the later version of ios7 but the phone will still be perfectly useable.

80 doll

Obviously you need to Google 'iPhone 5C deals' to find the cheapest deals and do some research about the phone on the Apple website.

If your contract is up, then I would upgrade to a newer version by trading it in. They now take trade-ins and you can get a new contract, so it may be just like getting a free upgrade. Thats easier then selling it on your own.