Swap Blackberry Curve 9300 3G for iphone 3gs or phone plus cash for iphone 4 ?

I have a 3 month old Blackberry Curve 9300 3G excellent condition. I miss having my itunes on phone so thats why I want to swap. Willing to swap for iphone 3gs or if its iphone4 plus i will pay cash. email if u are interested. Thanks :)