white samsung galaxy s3 10 days old swap for another phone plus cash -

Looking to swap my white samsung galaxy s3 for a galaxy s2 plus 200 or a iphone 4 plus 180 cash or a iphone 4s plus 100 cash. Im on the three network but think my s3 is unlocked as there is no brand name on the phone or the start up screen. It comes with box etc there is not one mark on the phone anywhere! If you are interested please email me. I really dont want to get rid of this phone as it is amazing but i really need some money. Thanks