Samsung S2 For Sale / Swap +

I have a Samsung Galaxy S2, bought it in Feb, 2012. Had a screen protector and case since first day so there are no marks or scratches on the phone or screen. The headphones have never been used, I have only used the phone and charger, box and headphones are good as new. I am looking to swap my S2 for an S3 or sell it for £225.