Not sure what you're talking about? Perhaps the price has increased over the years, but minecraft has also evolved (A LOT) since 2012, so of course the price has changed. Just because he's leaving doesn't mean he'll give away minecraft for free.
Are you kidding? Notch left because he DIDN'T want the money (well, partially). He left because he's a small game developper, and wants to continue coding more smaller games, instead of being stuck with a single game for the rest of his life.