What is a reasonable offer to a gym for using the facility to train?

by Mandy
(TX)

I recently became certified. I have been working out in the cardio kickbox class at a small martial arts gym for the past two and a half years. Since my certification, my instructor has asked me occasionally to sub her classes. This led us to briefly discuss a paid position. The gym is growing at an astonishing rate, and she needs trainers. I am not comfortable, however, with being put on payroll, as she has made it clear to me that if I am, every client I bring in will be their client, not mine. She also would expect me to work only for her and not outside on my own projects or with private clients. I want to draw up a proposal to present to her, offering my services as contract with reciprocal referrals (ex: sending my clients to the gym for cardio between training days, etc.). I would love some input and thoughts on this, especially what is reasonable to offer for use of the facility. Thanks in advance.