Generally the coastal teams have the big budgets, but currently in the NL it's the Central division that's locking up the stars.
Looking four years out to the 2010 season, there are 14 players currently under contract with two more, Zito to the Mets and Zambrano with the Cubs, likely to sign this offseason. That means 11 of the 16 players under contract or likely to be so for 2010 are with the Stros, Cards or Cubs.
Cubs in 2010: Soriano(34 years old), Derrek Lee(34), Ramirez(32), Lilly(34), Zambrano(29)
$ for these players= 76.75mm (estimating Zambrano at $18.5mm in 2010)
Cards: Pujols(30), Rolen(35), Carp(35)
Stros: Carlos Lee(34), Berkman(34), Oswalt(32)
Granted, young players such as Pie, Hill, Hirsh, Reyes, Wainwright etc... will have as much or more to say about the fortunes of these teams as aging, overpaid vets. That said, barring huge increases in revenues every year, the foundation for each of the NL Central contenders is pretty clear.
Who has the best core? Who will age the best or worst? What's the over-under on Lee and Berkman's combined weight when they hit 34? Will Oswalt turn into Tim Hudson? Are the Cubs nuts to go "all in" with these players? Can Rolen avoid the Inges, Chois, and Cintrons of the world for an extended period? Aside from Pujols, who is a mortal lock to perform?