I was looking at 2 sprint races ONLY, no practice due to the fact that some clubs offer full day practice, some half, some are trackday affiliates so it can not be compared apples to apples.
2 RACES 3 RACES
SMRI $100 $140
AFM* $125/140 $175/200
CCS SW $160 $210
WERA
sport $130 $180
WERA $150 $210
national
MRA $150 $170
These are the number I came up with, how you got yours I am unsure. I did not want to register with MOM to get thiers.