If I understand it right this is the deal. Chris felt like he had to keep a close eye on everybody because the park was always filled with strangers. Now that it's a member only thing he can loosen the leash a bit. No more start times or very organized runs. No more waiting for open weekends, etc.
The $100 sounds like a lot but if you go there twice a year it's not bad. A feel like I pay about $50 a weekend between the park and campground just about everywhere I go. If it is cheaper, like Harlan, the cost of gas from near Raleigh makes up for it. Also, the price of the park seems to be a small part of the price of being in this hobby. Buying/building the trail rig, buying the tow rig, fixing the trail rig, etc. costs a lot more than the difference between a $40 and $50 weekend.
Finally, for me Chris's spotting had value too. He has so many tough obstacles and known lines that I felt like I was in driving school and that I was actually a (slightly) better driver at the end of the weekend than I was before it.