this very helpful link to share with those of you who enjoy suds with the national pastime.
From the link above, it appears that your $20 will go farthest at Chase Stadium in Phoenix where the Diamondbacks ply their trade. Keep in mind this does not include tickets, parking or other incidentals--like airfare from Jersey to AZ. I lament the fact that the days of taking your youngsters out to the ball park for a wholesome afternoon or evening of cheap family fun are long gone--unless you hit the Minor league parks.
Some of those parks also carry some great craft beers, but I'm pretty sure even they won't let three of them go for just $12.
Anyway, just click on the link for your team to see what kind of mortgage you'll have to take out to enjoy some beers at the game.