Years? Exaggerate much? I'm not a game dev, but when I think about the projects that I've put literally years of effort into, they are far more complex than the typical <$10 app store game.
yet charge ~10$.
Games can be incredibly complex, you're underestimating
the amount of effort it takes to write one. You're also
assuming that he's selling his game on a mobile app store,
which may not be case (there's Steam, Desura, and other
online portals).