Well, you did overpay for Mauer, but if you can keep him for a long time at that price it will be worth it.
Let me begin by saying that it's a good team that will compete. 16 team leagues dilute the pool a good bit, and you came away with some bargains. That being said.
You need to improve at 2nd. Grudz is the starter in Chicago now, but will not be by the end of the year. Todd Walker, though a butcher with the glove, can hit, something Grudz can't do on a regular basis.
Rich Aurelia at $3 may be overpaid. He's flat-out terrible. I wouldn't want him starting for my team.
I think that you could very much use another starter. Halladay will not be able to carry your staff by himself. Someone that is often overlooked and very cheap: Kip Wells. The Dodgers are talking about trading Odalis Perez - beware. His value drops dramatically if he leaves L.A.
Anyway, good luck. You'll be in the top 5- absolutely. Shore up your starters, grab another closer, and you'll win.