I found Rapoo 8000 Wireless Mouse & Keyboard Combo in Robert Dyas. It is cheaper, nearly half price. But at Harrow (HA1 2DX) is clearing it, so the price is £ 7. Though it is made in China, it is worth the price. And 2 AA batteries is pre-installed. I can directly use it without buying batteries. And it is said that the this combo can be run more than 12 months with only 2 AA batteries.
I find it again on http://www.amazon.co.uk/dp/B00I97CFQS,
but it is sold at £17.22. So I cannot wait to recommend it to you!
I hope you like it!