Baseball Prospectus has a good look at the team-by-team compensation in 2011.
Of note:
*Carlos Lee takes up 24.45% of the Astros' total payroll.
*Roy Oswalt is the 4th-highest paid player on the 2011 Astros.
*Lee and Oswalt account for a third of the payroll.
*The Astros dumped just under $13m in payroll from 2010 to 2011, and their payroll is $18.2m less than the average.
*11.05% of the 2011 Astros' payroll is used on players who do not play for the 2011 Astros.
*The average salary of the 2011 Astros is $2.589m (among 30 players). Take out Carlos Lee, and the average salary is $2.024m.
*The total salary of the active roster seems to be (double-check if you like) $43.733m. Carlos Lee, Brett Myers, and Wandy Rodriguez make up 78.9% of the active payroll ($34.5m). That has been worth 3.7 WAR.
*In 2010, the Astros paid Brett Myers $750K per 1.0 WAR. They've paid him $5.53m for 0.4 WAR so far in 2011