It can vary, but the quotes of 30% to 40% taken by the owner are in the ballpark. I’ve paid anywhere from a very low flat fee per month ($100 a month for 10 hours a week access, ended up being about $2.50 per hour) to 40%.
Your negotiating points to help you come up with a fair deal:
How much space / equipment you have to offer
How busy you are at the time the trainer wants to use the facility
Whether you will be posting any of their marketing materials
Whether you can grow each others’ businesses due to differences in offerings.