How to give access to resource based on different fee policies

Hello.
I have a resource that I want to charge fees for one organization but another can use the resource without any fees. I am trying to figure out the best way of granting access to users based on if they have a cost center associated to their group information versus no cost center in the group information.
To keep it simple for the users that do not need to pay fees I do not want to make it required to provide a cost center in the booking window. However for the users that need to pay I also want to make sure I can collect the cost center information from them. Can I give access to the resource via two different means? Direct access to the resource for the users that do not need to pay and access via service request for the users that need to pay and make the cost center field required in service request form?
Is this the best solution, does anyone have any other suggestions that are better?
Thanks for the feedback.