Great seats!
I've been coming to Cardinals games since the place opened and I love the pavilion level. We've always had a good look at the field from there without spending a small fortune on tickets. 342 was just above first base so you'll have a good look at the throw outs and the view is good enough that you'll be able to tell whether the runner was our or not. The Cardinals dugout is also along the first base side of the field so if you're camera has a strong zoom, you should be able to get some decent photos of the players. If I know I'm going to be sitting on the upper level, I'll just walk down field level before the game to catch home run balls during batting practice or seek autographs from the players. Only downside to that is the gates usually don't open until 1 1/2 hours before the game.

Finding tickets for Cardinals games requires a little bit of creativity since they're one of the most popular teams in Major League Baseball. You can no longer just walk up to the box office and purchase tickets since they're often sold out. If there are tickets available, the ticket scalpers almost always beat the regular fans to the punch and then just stand along 8th street trying to resell them.

Getting to Busch Stadium couldn't be easier, it's easily accessible via highways and the MetroLink. The Metrolink operates on the honor system so you can sometimes ride without paying but if you get caught, you could have to pay a small fine.