I have been given an old iphone (iphone 3g) which is broken, the back is cracked and there is water damage. Apple have offered to 'replace' it with a new one of the same model, sim free, at £130 cost to me. A local phone shop has offered to open it up and try and dry it out- £25, but this may not work and if the shop cannot fix it then apple won't replace it (because someone else has tampered with it) so I don't really want to take this risk. the woman at the apple shop told me a brand new iphone would cost upwards of £400 (for a better model, but i'm not too concerned about this) but what I'm concerned about is getting the sim- by the time I have factored in data allowance, texts, minutes etc on a pay monthly sim only tariff, would it be just as good value to get an iphone from o2/vodaphone/etc thats included 'free' in a monthly price plan?