Trade in iPhone 5 for iPhone 4s?

I have the white iPhone 5 and I've had it since December. (It has a small crack though.
However, I Really Really want a white 4s…
I have a pink iphone 4 that I had before the 5.

Should I trade in the pink 4 to get money to buy the white 4s or trade my iphone 5 for it and where would I do it at?

Please Please Help

White girl probs

Here are your options:

1) wait until your plan is up and upgrade (downgrade) go the iPhone 4S.
2) sell both of your phones and try to make enough money to buy the unlocked iPhone 4S off of amazon or some other website. They cost like 500-600 bucks.