MM-$200 is the entry for the sprint races if you are doing BOTH the Enduro and Sprint races. Combined it is $1,000. Only people I know that would get those prices are Glenn and Dr. Frank.
If you are only doing the 3 sprint races like all but 2 of us the entry fee is the regular $325. With that comes one less sprint race and one less practice or qual whichever way you look at it. Another problem is sharing the track with Group 7 which (no offense Martin) will likely cause caution flags resulting in only a few laps of green racing.