£0 + £36 x 12 = £432
GiffGaff (buy a SIM-free phone anywhere you like)
£320 + £10 x 12 = £440
GiffGaff is 250 minutes per month, unlimited data, unlimited texts and an unlocked, unbranded phone. It also has no contract term, so you can jump ship when the iphone 5 is announced and get a lot more for your unbranded, unlocked handset.