Not a rallycross. We would be doing an autocross, which is a wholly different thing. Since we are still gauging interest and discussing how we can schedule it in such a way that participants wouldn't need to choose between the dyno or an autocross, I can't really quote a final cost right now.
We are considering doing it as a pay per run, or pay per heat event right now. Once we get a good amount of interest in participation of an autocross we will know what the price will be. Depending on how we schedule it, the autocross will most likely cost $35 as pay per heat, or $5 as pay per run.
All you need to run is a car that will pass a tech inspection, a helmet that is Snell rated SA85 or M85, and be at least 16 years old and a licensed driver.