As Jsyeagle noted in the comments, Forbes once again has ranked the Marlins organization as the least valuable. (monetarily)
The Florida Marlins' worth increased 8 percent, but the team ranked last in value at $277 million. Pittsburgh ($288 million) and Kansas City ($314 million) were among the bottom three.
If you would like to peruse their findings for all teams, click here:
Baseball's Most Valuable Teams
Personally, I put very little stock in this since Forbes doesn't have access to the team's books. But that doesn't mean it isn't a good guess. However, it is still just a guess.