iPhone 4s – the upgrade

Nice chap in the O2 store in Manchester on Saturday. Basically explains the following: 1. my next free upgrade is due end of January 2. I can “fast track” my upgrade NOW if I pay £245.00 3. I can buy a 64Gb 4S NOW on the same tariff for £145.00 4. They will pay me £280.00 for my old phone Net effect – I am £110.00 DOWN. Or…… I wait until 1st February and 1. They will pay me £280.00 for my old phone 2. I can upgrade free 3. The new phone will cost £145.00 Net effect – I am £135.00 UP. So – for a 15-week wait – I am £245 better off. Which means that O2 are paying me £16.33 a week to NOT do business with them. Is it me?