The Retina display, long battery life, 2.4GHz quad-core processor, and Touch ID are all here for just $425 at StackSocial.

Like most Apple products it can also get expensive if you start adding extra RAM and more internal storage. Buy the 15-inch model with the maximum specs, and you'll face a bill of well over £2,300. Once purchased, the Air is also not upgradable, so make sure you add what you think you'll need at the checkout.