It sounds a great idea but don't forget that, on top of circuit hire, you have MSA permit fees, expenses for timekeepers, scrutineers, rescue and recovery/snatch vehicles etc....and some sort of refreshment subsidy for the marshals to factor in to the 'cost per minute'. You also need an MSA organising club to take it on and get the permit. Nothing there that's insurmountable however.
If you want a clerk of the course, I'm cheap to the point of being free!