How to buy an Iphone relatively cheap?

I had an Iphone 5c, but I got it 'taken' by the person who payed for it.
Basically, I want to know how I could buy a new one on my own account that isn't so expensive.
I would prefer Sprint because that's what I'm familiar with, but I'm going for whatever is cheapest.
All I really need is unlimited internet access.
ALSO, considering the Iphone 6 is coming out, should I just order that one, that they said would be around 200 bucks?

What?

200 on a new contract. 5C is free on 2 year contract.