i only saved up a couple of hundred to be honest, i was pretty broke after driving lessons and test etc haha.
probably spend £15 - £20 food shop a week
then an extra £5-£10 getting lunch on campus or take aways :P
i spend £10 - £20 on a night out (often in freshers)
books at the beginning of uni might cost you £100-£200 depending on your course and how many books you need to get. buy them off amazon not the university book store.
then whatever extra you spend on clothes and other bits and bobs, which doesnt have to be much.
then rent. which i'm assuming you'll have a maintenance loan for
you may want to try and get hold of some money from freshers haha, msot people dont go overboard, but even i spent nearly £100 that week haha. i know someone who spent £800 :O
so total first year spending per week for everything, in general (sometimes more, sometimes less, obv) = £60
second year average = £30 (because i havent been out for months and have learnt how to food shop efficiently, and am broke so cutting down on everything costs XD)