System Administration Cost Studies?

davodavodavo asks: "I'm a market researacher looking for any industry data on the costs of administering UNIX, Linux and Wintel server farms. I've got the overview stuff (Gartner grp), but I'm looking to build a fairly detailed cost model. Specific focus are the activities of server configuration management -- binary images, software distribution, and application deployment. How frequently does some part of a server's software stack have to be updated / upgraded? Any data along the following lines will be appreciated: amount of time it takes an admin to update 50 machine; frequency of distribution or configuration error requiring a roll-back to a previous configuration; average time to perform a rollback; and so forth. If anyone knows of a good detailed model on this topic, please send pointers! I will happily provide the results of my work to the slashdot community (if you are interested, please email me). Basically, I am simply trying to understand the economics behind server management."