One of the best games ever on the DS and playable on the 3DS / 2DS / new 3DS. Not recommended for children! It's been cheaper but not for long and it sells for £10+ used on ebay.
Also if you happened to have purchased a game from thegamecollection via a TGC outlet eg amazon, rakuten then you can get a 10% off voucher at http://www.thegamecollection.co.uk/vc
(you just need to enter name, email and order number)