looking to SWAP my iphone 4 and cash for an iphone 4s ?

Hi I am looking to swap my immaculate 16GB black iphone 4 and cash for an iphone 4s. I would prefer the Iphone 4s unlocked, or on orange network and it must be immaculate condition. Get in touch if you are interested. I will not post. Face to face dealing only so no scammers. Thanks