Independent labor charge?

I am a former Marine Corps network administrator. As I have never done my job in the civilian sector, I am not knowledgeable as to pricing for labor. I am doing some independent work for a gentleman that I hope to keep as an influential future contact. I would like to be able to undercut any price he could get from an IT contractor, but I still want a price that is fitting for professional work.

Details: I am going to set up a Windows 2008 server, install and configure (basic configuration) both ADS and WDS, and ensure that new workstations are automatically configuring on the domain.

Any help is appreciated, and if I can provide any more information, please let me know. Thank you.