iphone 3gs 16gb will swap for good blackberry *

i have an apple iphone 3gs 16gb with the ios 5.1. this phone has scrathes on the back which happens with the backs of iphones and ipods.. it has no scratches on the front and looks brand new from the front. not buttons or anything are damaged! this phone has never give me trouble.. would like money but would swap for a decent blackberry..also comes in box with wires and charger!! thanks text only 07754034858