It available for £29.99 pre order which I though is a pretty good deal. Nearest I could find was £31.99.
If you use the £5 voucher posted by WonderWoman and add some DS stylus' to make the order over £30 you can get the game for basically £27.98 ...and some spare stylus which may or may not be handy especially as they are pink!.
Also, there is up to 11% quidco which makes the game potentially even cheaper!
They have a release date of the end of March which differs from other sites, but I see no reason why they wouldn't ship if the release date is in fact earlier.