Good question. For a single day local professional event here, this is what I would approximately expect my costs to be:
Tire wear up to 50% but more likely 25% ($300-600)
Brake pad wear about 50% for street pads ($100-300 depending on pads)
Rotor wear I'm not concerned about
Track insurance for $50,000 around $300 (many people skip this)
HPDE fee with full instruction ~$600 vs lapping day fee ~$250 (this varies widely)
This doesn't include travel but for a single day, almost half the M-school. I never thought about it that way. Makes M-school seem more reasonable.
I've been to the track several times in a much less expensive car but I plan on going in the M this year.