Hello Yogi Johnson,
In situations like this, I make calls to area facilities for prices. You also want to make sure you receive the minimum amount needed to keep your business afloat. My rates gradually drop as the participant number rises. Think of it as the class participants sharing your hourly rate.
I hope you hear from trainers in your area.
Natalie aka NAPS 2 B Fit.
In a case like this one I would either charge my hourly rate no matter how many participants show up for the class or the second option (not my favorite) would be to get a % of each participant that will sign up. You can check the local rates, but at the end it comes down to how much you want to make in order to be worthy of your time. I hope this helps.