Here's an idea that might help both NESBA, and the members at the same time.
During every track day, hold a drawing for only those who are registered riders for the day, or at least registered members. Each ticket is $5.00 with a limit of 5 per person (maybe). At the end of the day, the Director draws ONE ticket as the winner of a FREE trackday. You could always draw another one for a t-shirt or stickers.
The idea is to raise some money for NESBA to donate to the air fence fund, or another need as they see fit.
You would only need to sell about 40 tickets each day to make a donatable amount.