If you are really keen on a new iPhone 4S, you might well be in a queue now. In fact, you might already have one, as the Apple stores opened their doors at 8am for the good folks who queued up in the changeable autumnal weather. But if you are still undecided about an upgrade, maybe the pricing at Tesco Mobile might convince you?There are some good deals to be had, but as ever, Tesco is warning on low stock levels. It took months for some proper availability for the iPhone 4, so if you want one, you probably want to be pushing your trolley round this morning. Or at the very least, giving your local store a call about availability (if you want to save the petrol money).It's all about the total figure with Tesco, so perhaps getting your calculator out is the best thing. But to our eyes, the opening deal of £25 over 12 months, plus £335 for the phone stacks up well. That's a total of £635, which includes a monthly allowance of 250 minutes, 5,000 texts, 1GB of data and unlimited Wi-Fi. After 12 months, the phone is yours to sell or load with a cheaper SIM.Other deals are available too, including a 'free' phone option, but that's £45 over a 24-month period. Yes, the allowances are more significant, but if you want value, that's not the deal (you'll have paid £1,080 by the end of your contract).You can see the full breakdown here, where you can also pre-register for a handset. Probably a wise move. Oh yes, you get Clubcard points too, should you like to accumulate those too.In terms of the other networks, Vodafone has just reduced its pricing, with Orange and T-Mobile details here and Three details here. SIM-free is also available, but there's a wait to get one right now.