This is why I was suggesting the GTX 780 may be expensive, but according to Mr Krugga it will fall in line with previous gens Circa £400. Which would be awesome if true.
Like I said before, this is not anything set in stone. It's crucial to understand how UK pricing works with the graphics cards (and other computer related products).
We have Nvidia, the actual manufacturer of reference PCB and GPUs, who have their general costs of producing a batch of 1000 cards figured out (for at least a few months, because the costs change too) and they add their hefty mark up on top of that. Except it's nowhere near as large as some people might think. There is a lot of associated costs, some of which are not as easily apportioned, namely R&D and marketing. These will all have to be spread out, with the costs of parts and outsourcing manufacturing included (AFAIK, they still don't use their own plants for production), then the ready parts with that set batch price can be transferred onto Nvidia's vendors, who will or will not be to pay for the cards. The general MSRP will be agree on with the largest AIBs and that will include the predicted mark up for US retailers and any middlemen in between (think third party suppliers, logistics). AIB's role in this whole thing at launch will be to ensure the availability of the products in shops and providing support/warranty for them. They pretty much throw in some accessories, put the sticker on and box the whole thing up when it comes to reference designs.
When OCUK makes a deal with a vendor (such as MSI/Gigabyte/EVGA or maybe even a third party supplier), they agree on the price for a more or less specific number of cards, with the intention of purchasing more if the demand is high enough. At all times, customs and taxes come into play, with final price being affected by the VAT. One of the biggest things that will affect the UK pricing is something that's taught in basics economics - supply and demand. The American market is in a much more comfortable position when it comes to availability, hence why in case of short supply, the UK retailers pay their price and transfer them onto their customers. If Nvidia suddenly drops the price, retailers often receive rebates on future purchases or buyback offers.
That's at least as much as I understand it and my main drive behind making it absolutely clear that Nvidia (or AMD for that matter) doesn't have full effect on the UK prices.
The truth is that most profits come from mainstream/low-end cards (think laptops grade) and mobile devices (strong emphasis on this one). They need to win the enthusiast war only to stay relevant, the profits will roll on in the lower tiers of the business anyway.
Let the free market war begin!