Well, the key to getting value lies in two areas: First, the supply is a bell curve, with way more decent players than good one. So you should be using free agency to fill your holes where don't even have a decent player, and you should be able to do that very cheaply. Second, not all marginal wins are worth the same to each team, and money doesn't have the same value to all teams. If you have a crapload of cash (like the Yankees) or are a team that is competitive but not dominant (like the Cardinals this offseason), the amount you are reasonably willing to pay for extra wins can go through the roof.