Caregivers... How much do you charge/compensate?

I am trying to find a median on how much I should be compensated for my services to my soon to be patients. I know I should total the amount of electricity, nutes, and water, but what about the medicine itself? IN TOTAL HOW MUCH is a fair compensation price?

I charge the two people I help out $10/g. Just enough to recoup costs and to help expand the system a tiny bit. Eventually you can go from a couple of patients to selling your overages to medical dispensaries.