Nintendo has historically never made adjustments to the pricing of their products, except for when the games enter a "nintendo selects," classification, or only after extended periods of time (Mariokart 7, 2011, is worth $29.99)

This has the effect of not trampling on the resale market as well as keeping sure that sales don't slump because people are waiting for a price reduction. If you want to buy a Nintendo game, then you just buy it.