This site can help you compare prices:
http://www.pricerunner.co.uk/cl/27/Laptop-Computers
However if you wanna really get good price you got 2 other options:
1) Search for used computers, sometimes a year old laptops, that was the edge of the tech 2 years ago so they are way cheaper now and they are still better then the laptop you can get on the same price today.
2) You can go to shops that sells laptops that was sold by factories that either don't use them anymore because they are too weak or the factory doesn't exist anymore, you can get really nice price there.
Before you buy any computer/laptop I am suggesting that you think what are your needs exactly, get a bit better laptop then what you need but not a lot better, since there is chance that your needs will go up a bit in the future and there is no point wasting time/money for just a bit better laptop. Don't forget to think about how long you want the laptop to work for you, and base what you but according to it also.
Good luck finding the perfect computer hun.