I agree on lower spectator costs, I can't even begin to remember how many people have asked me how much it was to come and spectate our races and when I tell them the absolute majority pass on it. For example, I work with a guy who asked me last year about spectating, he wanted to bring his wife and 2 sons out to the races on a few Saturday's during the summer. When I told him he would have to buy a weekend pass, and that it would cost him like $100, he passed on it all together. The irony of that situation is that his sons ride off-road currently and could be potential racers themselves if they got hooked, not going to the track won't help that situation.
As far as how do you control racers not buying the cheaper spectator only passes at the front gate, why not have the person in registration confirm which pass each competitor has when they enter their races, that certainly wouldn't require any extra time or man power. If a competitor purchased the wrong pass then they would have to pay the upgrade fee to the 'racer pass' if they wanted to race (maybe even have a minor penalty fee associated with purchasing the wrong pass at the gate).
