Blackberry curve 8520 excellent condition +

blackberry curve 8520 on T-Mobile black and has a couple of scratches on the back of the phone. Comes with charger no box or earphones. Has a 2 megapixel camera. The phone costs only 5-10 pound to unlock on all networks. I would like to swap for a sony ericsson xperia ray, xperia arc or a Sony xperia u and cash on top.