£279 is a great price, probabily the best value launch ever considering what you're getting with it.
•Xbox 360 - £279
•20GB detachable hard drive
[That(+ the wireless controller) is the only real reason to buy the 400€ pack]
•Wireless controller
•Wireless Xbox Live headset
[I won't play live...]
•High-definition AV cables
[If that's a cable with good quality, it's useful]
•Ethernet cable
[Ehm? I have 3 or 4 unused ethernet cables here]
•Xbox 360 Media Remote Control (limited time)
[don't need that, I bought a DVD-Player ~3 years ago...]
•Detachable faceplate
•Xbox Live Silver membership
[doesn't cost anything and..., yeah you can't play online with Silver ]