Build it, they will come...
Honestly I got involved in a deal like that and they will come...
BUT... the problem we had was with financing the thing "until they came"
Medical, track rental, Ambulance etc.. The track did not give us any cut from concessions but we got all the gate.
Volunteers are really the key.. you will find a lot that do volunteer but "reliable" is another problem..
The track also required that we use their "Tech inspections" guys and I can agree with that but they need paid too..
I think our final cost was around $800 per night (10 years ago)
It was totally gratifying to make this work for the organizers...
You do need to get this laid out on paper (talk to the track owner for what you really need to have lined up for staff)
I am in Ft Wayne and would gladly donate my time for this if you decide to go for it....
http://www.munciedrag.com/