Details of Windows Vista’s UK price have leaked online after retailers started accepting pre-orders for the new OS, and the early signs are that it’s worth shopping around as the asking price varies between sites.

Amazon's UK site lists Vista Home Premium – the version we predict most consumers will plump for – as £219.99 inc VAT for the full boxed product, whereas at you’ll pay £182.11 for the same product. If you want to get hold of the Ultimate version of Vista: Chillblast wants £323.11 inc VAT for it while Amazon is asking £369.99.

Microsoft has made it clear from the outset that PC manufacturers and retailers will dictate the final pricing, but we’re surprised to find such variations.

What’s more, Microsoft told PC Advisor not 10 days ago that it was intent on keeping mum about the retail price of Vista right up until it launches at the end of January.

Now it seems online retailers have once again let the cat out of the bag. Amazon's US site revealed US pricing for Vista when it posted preorder details on its site back in late August.

The prices - ranging from $99 for an upgrade to Home Basic ($199 for the full version) up to $399 for Vista Ultimate - were subsequently confirmed by Microsoft. However, no official announcements have been made to date about UK pricing.

As widely predicted, prices for UK customers are significantly higher than those in the US. According to prices listed at earlier in the year, Stateside customers will be able to get Vista Home Basic for $199 – roughly £102 – a full £50 less than Chillblast is asking for it. That’s a markup approaching 50 percent.

Vista Home Premium will cost £219.99 inc VAT for both Amazon’s UK customers and those heading to PC World. At an upgrade version will cost £149.99. According to our calculations, that’s 80 percent more than in the US.

Similarly, Windows Vista Ultimate – the bells-and-whistles version of the operating system – retails for $399 (about £203) in the US while PC World and Amazon UK are asking £369.99 for it.

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