How much money does it cost to trade an iPhone in?

I have an iPhone 4, but I don't like the update that I gave it, to the iOS 6. Parents aren't listening to me, 'cuz it's a money issue, so I figured, if I have enough money, I'll just pay for it myself, but how much would it cost? I just wanna trade it in for the same phone model, just completely new and without the update it.

Well a place you can trade it in at is a game stop but you will only get around $129 for trade-in for a 8 gb and a little more for a higher storage iPhone 4. They also sell used ones but a iPhone 4 16 gb is $299.99.

How to downgrade from iOS6 to iOS5
http://www.idownloadblog.com/2012/09/28/how-to-downgrade-ios-6-to-ios-5-1-1-a4-devices/