Mobile buyers are a pretty savvy bunch and know a good deal when they see one. Which is perhaps why the Google Nexus 4 has cleared out almost immediately on Google Play.If was a great deal too. A top-end SIM-free Android phone from £239 is alarmingly good value, especially if you grab a cheap data and calls deal to go with it. It certainly makes a mockery of the contract deals on offer. O2 has the network exclusive and is asking £36 per month over 24 months to own one. As we mentioned previously, the entire cost including calls and data is £864. You can get a similar deal for £479 if you go SIM-free.That probably accounts for the fact that the Nexus 4 is still available at both O2 and Carphone Warehouse, if you want to go down the contract route. Obviously, if you want to spread the cost, both are worth checking out.The Nexus 10 tablet with Jelly Bean also saw swift business on the first day, with stock also cleared out for the time being. That's both the 16GB model (£319) and the 32GB Nexus 10, which sold for £389. Google is promising more stock of both devices soon, but if you want either for Christmas, we recommend you are very quick off the mark when the next batch lands. Don't say we didn't warn you.