Just out of curiosity I was checking out tickets available for tonight's game. Some very cheap tickets available for instant download. Of course it depends on whether you care where you sit or not. For example tickets in section 334 for $5.30 each. Even some really good seats for $40 each. It's not like that for all game days and opponents but good to know if you ever want to catch a game last minute and not spend a fortune.
...took me awhile and several dollars but I finally figured out that the best way to handle the prices at the ball park is to leave a couple of hours early and hang out at one of the many Yankees pubs near the stadium...eat and get a good beer buzz before going to the game.