For now, I would like to describe one real-life scenario of a middle school in Southern California that, in two years, has built a complex television studio where students produce a live weekly news program that airs throughout the school and simultaneously on the Internet.  

As with any new school, money was available to develop an elective program.  With an initial investment of approximately $30,000, the school purchased two Panasonic SVHS cameras, the Trinity System, and assorted items including studio lights, microphones, tripods, etc.  The editing system was already available due to a transfer of equipment from another school in the district.  This particular editing system was a $15,000 linear system.  Today, a more advanced system could be purchased for $5000 and it would be state-of-the-art nonlinear.  

We continued to write grants and received additional funding from our local education foundation, receiving two grants over a two year period totalling approximately $15,000.  
 
 

Another important funding source for us has been the local cable company.  Through its Community Access Foundation, we have secured grants for equipment purchase.  Our show airs during a regular weekly timeslot on local cable and so a relationship was started with the company a number of years ago.  They initiated the grant program with us.  Additional support was received from the local cable company as they donated all of the coaxial cable and some manpower to wire each of the classrooms with cable from our control room, allowing us to broadcast live to each classroom.  

Parents are another excellent source of funding and donations.  When we needed to purchase some equipment as part of a matching grant, our parents donated $$ to the program to purchase hard drives for our new nonlinear editing system (donated, by the way, by a leading edge video broadcasting company).  

For used equipment, touch base with local cable and broadcast television stations!