It's a fantastic read, and despite its being published in August 2008, is still very much relevant.
The Biz of Baseball - one of the best baseball sites out there - broke down the Astros organization from a business standpoint. You really should read the whole thing, but here are some nuggets:
Since the purchase of the team in 1993, the Astros rank second in the National League and fifth in the Majors in winning percentage (.534) over 15 seasons from 1993-2007. Since 1998, the Astros have attained an astonishing amount of success, which can compete with the run of the Yankees and the Braves. Since 1998, they have made the post-season in six of those, with Wild Card berths in 2004, and 2005, along with Division Titles in 1997, 1998, 1999, and 2001. Along with all those accolades McLane’s highlight, was 2001 as the Astros were the Organization of the Year by four separate media outlets; TOPPS, SportsTicker, Baseball America and Baseball Weekly.
-From 2002-2008, the value of the Astros (from Forbes) has grown from $337 to $463 million. Want to know what impact two deep playoff runs has on a team's value? Starting 2004, the Astros were worth $320 million. Following 2005 they were worth $416 million.