Roger has nothing to lose by dropping the entry fee WAY down for classes with no entries like class 9. There is a break even cost that covers insurance and such so he can't drop it below that but I'll bet he could drop it to $999 and see if any 9ers show up.
NORRA has had nines show up and offer an air cool discount. Could be best way to go as it has a great format and not endless silt as SCORE seems to have now. I had a Manx 9 project for NORRA but I had to postpone my racing for a bit.
Like everyone has pointed out its all about the costs. Class 9 is a budget class and racing SCORE and having a budget don't mix well. You could run all year in a local series for the cost of the Baja 1000. You will see a car here and there only because guys have it on their bucket list.