Hi all, just wondering if the following is worth me doing... I currently have an iPhone 4 on a 24month contract which runs out in June and ive just been offered £300 for my iPhone. Im thinking if i sell it and put another £200 towards it i could buy a new sim free iphone 4S! and then put my contract sim card and carry on using. Then come May/June time i will be due a new upgrade so would get the latest phone out then at the time aswell and sell whichever. Is it worth the extra £200 now and possible higher resale value come summer time?