you could probably put one together for less but then you have to fork out for the windows (if you want it legit) which is usally £100 odd plus on its own. unless you go for linux (or alike), which is brilliant for browsing and has windows compatible excel/word ect.
only downside to linux in my experience is i cant play games like command and conquer, so i have duel boot with xp

i recommend overclockers, ive just ordered my case and psu, cant wait to get building.