swap xperia arc s for iphone4 or for sale £170ono *

i am only wanting a swap as my partner has an iphone 4 and i need one for easyness to send things between and i have an apple mac pc which is easier to use with an iphone. the xperia is 1 month old and has no scratches comes with a hd camera and epandable memory in great working order an amazing smartphone still got box and stuff inside i.e charger and usb cable i need a swap asap as i am due a baby soon and need to get used to the iphone before i go in