Please help £700 computer biuld

[C4LL4N]

Hi guys i had my build planned out but have landed myself in a rather rubbish financial situation thus i must limit my new build to £700 The main use for the the computer will be bf3
Any help appreciated
C4LL4N

 

[metal orient]

First step:
http://www.tomshardware.co.uk/forum/261222-13-build-advice