You looking at it in a shop, on an online retailer, or on Nintendo eShop?
Because the eShop never lowers it's prices for it's major titles, ever.
You should be able to find it a little bit cheaper in shops and online. Amazon is showing it at about £25 (used) to £33 new, while Game.co.uk (UK games retailer) is selling for £33.99 new online, but may be cheaper in shops or pre-owned.
That's a drop of about £9+ from release, which was a couple years ago?
It's not an amazing drop in price, but it's really Nintendo's fault, since they're clearly still supplying it at a high price.