It takes two to tango when it comes to Free Agency. (see: Why he won't become an Astro, Andy Pettitte:). The question about any list is this: how interested in Houston is the Free Agent? The question is never about how much Drayton McLane is willing to spend (see: Beltran, Carlos or Lee, Carlos or Kent, Jeff or Clemens, Roger or even Pettitte, Andy).
So who on the list that is a pitcher might be interested in Houston? Well, some will and some won't. Some because of geography, some because of friendships on the team, some because of money and some because they feel the offense and defense behind them will allow for good things, including a chance to go to the World Series. One thing: veteran free agents do cast a jaundice eye on teams that rely on too many young prospects. Remember, potential only means you haven't done anything yet. So there is a difference for a Free Agent between a good young team with potential and a good mix of veterans and youngsters with a rock solid core of players who are the primary contributors to success or even failure on a team.
For example: Lance Berkman, Roy Oswalt, Jose Valverde and Carlos Lee would be seen by a potential free agent as a good thing. JR Towles and Michael Bourn perhaps not so much (unless Cooper decides to let those guys play more and reach more of their potential). If the team relies on Darrin Erstad to start more, they may save some of this season, but what Free Agent is going to look at that as a good thing that a veteran like Erstad instead of a young player like Bourn performed best? BTW - I think Houston needs a catcher from the free agent pool as well, one that is a respected and well liked... but that's just my opinion. Nothing better to lure a good FA pitcher than a rock solid receiver on the team. Just saying.
So who comes here next year is not predicated on McLane spending, he will. It is predicated on the free agents view of the team and what changes they can reasonably make (veteran frontline catcher?), what progress young players make from here on out (Towles maybe, Pence and Bourn, a return of Paulino maybe) and what they think about living in Houston for a while.
I think Houston has a chance to lure good FA pitchers, but it sure would help if guys like Towles, Bourn and Pence prove they can play *consistently* in the majors and Houston wouldn't have so much of a reliance on guys like Miguel Tejada overall.