Picking up on SSB's idea that expanding the budget by pickign up expiring bad contracts and eating some contracts in trade might be a better move than picking up Fielder, think about a combination of (1) dealing for Bobby Abreu to bat leadoff (maybe sending Flores or maybe someone else) and play left and (2) eating most of LaRoche's contract, tossing in a pitching prospect, and acquiring CF Brett Jackson from the Cubs (their #2 prospect).
Abreu, even with his power drop, is still about 40 - 50 OBP points better than any other leadoff candidate on our roster (not named Werth), based on season numbers. Clearing Laroche allows the team to move Morse back to first. Jackson already is better than Bernie and could start in a platoon with Cameron, and has shown very good OBP in the minors. If he pans out, he can leadoff when Harper is ready and Abreu can be dealt, or, if he does not, he can be a good 4th OF. Getting a decent leadoff hitter would add a lot to the offense. Fewer times RZ comes up with 2 outs, more times RZ and Morse /Harper come up with a runner on, etc...
This type of move would cost about $14 - $17 MM in 2012, depending on how much salary you eat. Really even less, because we are stuck with the cost of LaRoche unless we find a team willing to eat his salary and LaRoche would be sunk costs in a Fielder deal as well. If a Jackson pans out, maybe we don't even need to pick up a CF next year, but if he does not, we can still pick up a Bourn /Victorino next year.