Terry, thanks for taking the time to respond. A couple of points.
You are NOT required to make payment *in advance*. As a convenience to our entrants, we have made arrangements to accept credit cards.
How is paying by credit card not paying in advance? I'm confident you're charging the cards at time of entry, and I'm confident my credit card company will require payment if my card comes due prior to the event. I I cancel I lose use of those funds until they are returned (minus a $30 fee).
If you chose, you can register online and bring a check to registration.
That's good to hear, Terry, however the supps read as follows:
Registration is not complete or guaranteed until payment in full is received. Payment may be made with Paypal, mailed to the registrar with a paper entry or mailed separately if registering online.
This does not necessarily "jive" with what you're saying here. But, if I choose this option of bringing a check with me to registration, how am I affected by the "not complete or guaranteed" clause, and if cancel my registration am I still subject to a cancellation fee? And how would you collect it?
A $30 administrative or cancellation fee is not out of line for an event of this type; a commercial enterprise would probably have a higher fee. There are costs involved in a cancellation including the bank fees that the region was assessed for the canceling driver's original credit card payment.
Well, this is not a commercial enterprise...And, if you didn't require prepayment then there wouldn't be cancellation fees to the region...
Terry, when I re-think my initial thoughts on the subject, as described yesterday, I think the part that bothers me the most is the requirement for prepayment and the cancellation fees. Maybe the vast majority of the club racers have excellent cash flow, and they can plan their lives weeks (or more) in advance, but as my close friends know I have a lot of irons in the fire in my life, with racing being a lower item on the priority pole than many others. I am perfectly happy with pre-registering online to give the registrar a "head's-up" that I'm likely to show, but that does not guarantee I can or will. Thus, I REALLY don't appreciate being required to pre-pay for an event when if, for whatever reason, my life changes a few days in advance. Instead of simply sending an email to the registrar to let him/her know I can't make it (which I've ALWAYS done) I now have to deal with pulling an entry and waiting for someone to return my money (and having part of it withheld from me).
The whole point of a pre-registration discount is to encourage drivers to enter early, in order to give the registrar the opportunity to get a lot of work done in advance of the event. However, if this new-to-us system in terms of late entry and cancellation fees is the way things are going to be from now on then, at least to me, that incentive is lost; you've effectively increased my entry costs because I will choose to paper-register at the track (increasing the registrar's workload as well as my costs).
If, however, I am to infer that, in deference to the supps, I can actually register with DLB online and bring a check to the track (with no real no loss in terms of the validity of my entry), and as a result I won't be charged a late fee if I cancel in advance of the event by notifying the registrar (which, again, I ALWAYS do), then it's a wash, and I'm OK with that. However, short of your explicit approval of this behavior, I'm doubtful that's what's intended or allowed.
As for the track's charges and choices, you're right: market forces will win. To that end, they're not getting my entry; scratch that marginal revenue from their books.
Terry, again, thanks for taking the time to address my concerns, I appreciate your clarifications.
Greg
A big thanks to Joe Volpe for providing a top-notch environment in which to work. 
Maybe you could put a call in, maybe they might call you back.