my galaxy unlocked s2 and £90 for your newer s2? ?

i have a white galaxy s2 it has a few marks on it. it doesnt have a box but has charger. it is unlokced. i would like to swap it for a s2 black with box and accessories. i need it to be unlocked or on vodafone as this is the network i am on. i bet you are asking yourself why am i doing this, the answer is i have had my white s2 a while and would like a newer looking one with accessories. and black of course. i can collect if needed but you are also welcome to collect from my home too.