Currently the 5DIII is about £2,300 here in the UK and I guess the 7DII will be around £1,500 at launch (give or take).
You forget that the retailers will do their normal 'fleece the early-adopters' routine, where all those must-have-new-shiny-toy-NOW! people with more money than sense (or who buy their cameras with somebody else's money) will pay anything to be the 'first on the block'.
My prediction is that the 7DII will launch in the UK at £1800 to £2000 and will stay at that price for a few months. It's possible that one of the retailers will blink early for the Xmas period - and that prices will do their normal plummet around then. But I reckon they'll be able to hold out until January. By Spring 2005 the 7DII will have dropped down to less than £1500.
This is standard practise for UK retailers. Check out the history on the 70D's price at CameraPriceBuster - HERE. It's standard practise, but there will still be loads of bleaters complaining about 'rip-off Britain'. If you don't want to be ripped-off just wait a few months. Nobody is forcing you to buy the new camera now.