munro harrap: In the UK costs are doubled: £529 for 16Gb (a £20 SD cards worth)
£599 for a 32 Gb model, and £699 for a 64Gb model (£60 SDHC UHS-1 cards worth)
The prices you are quoting are the simfree/unlocked prices direct from Apple UK with no monthly contract. The prices in the article are on contract and are lower due to the subsidy.
One on contract example here in the UK, Vodafone at £37 GBP per month gets you unlimited minutes, unlimited text and 1Gb of data. The upfront handset cost for the iPhone 5 with this 2 year contract is 16Gb at £99 GBP, 32Gb at £209 GBP and 64Gb at £289 GBP
As usual, the upfront cost of the handset (as well as the included minutes and data) goes up and down if you choose to spend less or more per month respectively...
£42 GBP per month = 16Gb at £49 GBP, 32Gb at £149 GBP, 64Gb at £229 GBP
£33 GBP per month = 16Gb at £149 GBP, 32Gb at £269 GBP, 64Gb at £329 GBP
See here for the rest of Vodafone's offers on the iPhone 5...