As a non-profit, you need to keep things on the cheap, and Freecycle is here to help.  It's a community of people who want to get rid of stuff, but hopefully send it to a good home.  There are communities in every city of people trying to just GIVE STUFF AWAY.  Think, you could furnish your whole office w/free stuff . . .  maybe.

http://www.freecycle.org/