Being in the Top 5 and busting the tax are two different things. Only Boston and Washington were in it last year, and I didn't see the Yankees or Dodgers or Cubs attempt to change that (at least not yet).
Greinke is an interesting one. The age is more concerning than the money, if he can actually keep pitching this way the money (assuming some pick-up by AZ and a low trade price) would be worth it.
Of course Arizona is only a game behind us in the standings. And Texas, for all the Mike Minor talk, is ahead of us.