How much trade value will sprint give me for a iPhone 5c if I want the iPhone 6s?

I have a iPhone 5c with cricket wireless, I was originally with at&t, it's 16gbs and white. Normal scratches, no cracks, everything functions. Also will the trade value amount be taken off the price I will pay during the purchase or my bill?

Here's an idea; pick up a phone, call sprint, and ask them.

Unless you go to Sprint the next time they have a any trade-in for $200 Promotion likely not very much. It looks like you need to use the serial number to get a price form the Sprint website.
You will likely just want to keep your iphone to use as an iPad touch or if you decide you don't like sprint and want to go back to Cricket

That you should directly ask to sprint as they will guide you better than the rest and In case you are looking for a good security app, I would suggest you the best app and that is Leo Privacy Guard.