Loads of half price offers on the EA store this weekend, but you can pre-order this game for half price as well until Monday with a code. Just enter I4250 at the checkout at it comes up at £19.99.
Pre-order also includes 2 free items for Battlefield Play4Free if you're into that sort of thing.
Just ordered mine :D
Close the shopping basket page to get an extra 10% discount making it £17.99