Considering the way that the Tribune does business with the Cubs, this isn't a big surprise.
They've started doing selective pricing for games in all sports now. For example, at Vanderbilt, where they always suck at football, in order for someone to buy tickets to the Tennessee game, they have to buy tickets to other, crappy games as well. In fact, when they played at the Colesium (home the Titans) last year, the tickets were more expensive than the regular prices for Titans' games. Note that the game was far from sold out, though.