The three best teams of the last decade were the Patriots, Steelers and Colts. All were in the top 10 in spending in a breakdown of committed cash from 2004-2008. La Coanfora did an interesting look at this.
http://blogs.nfl.com/2009/06/26/moneyball-nfl-style/
http://blogs.nfl.com/2009/06/29/more...ns-and-losses/
Money alone doesn't get you to the top and keep you there. Money plus good management plus good players gets you to the top and keeps you there.