1) George Steinbrenner net worth 1.3 billion dollars (wikipedia)
John Henry net worth 840 mill (March 06 Boston Mag), Tom Werner 600 mill (2002 Forbes most recent I could find).
SO yes the Boston has the exact same spending power that the Yankees have but I honestly cant imagine Henry and Werner's net wealth remaining stagnant the last few years....
2) Nintendo owns Seattle, Liberty Media owns the Braves, and the Tribune company owns the Cubs. Your Steinbrenners or Henrys cant compete with those 3 companies.