I'm thinking... Buy 16GB 3GS on O2 Pay & Go = £440 Sell 16GB 3G on eBay = about £250 looking at those ending now. Cost to me roughly £200 Presumably I can just put my Pay Monthly O2 SIM card in and carry on without signing a new contract? Unlimited data, MMS, visual voicemail will still work ok? If so then I can upgrade this year and every future year for £200 or so. This seems fair. The answer is to avoid the subsidy.