iPhone 4 16GB Black (ORANGE/TMOBILE/EE ?

Hi, here is my Apple iPhone 4 16GB in black on Orange/TMobile network. In fully working order but has some scratches on the front and back but otherwise in fully working order. Im looking to either sell it or trade it for an iPhone 4 on the 3 network. The phone will come with a box, charger and all paperwork including the apple stickers. Will also come with orange PAYG sim card so you can see the phone working. If anybody is willing to trade it for a 3 version I would also be willing to throw in some cash on top of the phone, just let me know what you have to offer.