Basically Nintendo's conservative about their printing runs. The games that sell forever obviously don't drop price because they keep on selling at that price, but even the niche stuff like Wario Land or Fire Emblem find themselves in that position because Nintendo pulls the plug on them somewhat too early, while demand remains roughly flat for those games, the supply dries up entirely, so they hold at normal pricing for a long time to come
Monster Hunter: pissing me off since 2010.