The Rotation

So Mike Pelfrey’s dominating performance against the Rockies got me thinking. Where would the Mets be (or where might they be able to get) without John Maine and Oliver Perez?

In other words, how much better would your favorite team be if instead of Maine and Perez we had two other starting pitchers? Hypothetically speaking, if Maine was replaced by Joel Pineiro and Perez with Ben Sheets in the Mets rotation, what would the Mets have (besides a slightly larger payroll)?