Johnny, this is only true if you have a relatively low power supply in the first place. Many custom built/gaming pcs/new pcs will have sufficient supplies. Although I admit it does have to be quite beefy for the job, especially for overclocking it.
Memnoch, according to my source
xe.com this works out at £111.75 which I would say is very very good, and much cheaper than it would be over here.