Here's what I expect from caregivers. If they do things this way I have no problem with them.
Give clear, explicit expectations for the patient's behavior, and give clear, explicit promises for what will be provided. Give a clear, explicit description of what can be provided, and the grower's skill.
Example...
Patient will not sell medication to others, patient will not call caregiver outside of daylight hours asking for more medication, all medication will be at a flat rate of 10 bucks a gram, minimum of 5 grams for delivery to be made, ALL medication from the patient's plants will be available first for the patient to purchase unless the patient has explicitly stated that they anticipate no need for it, at which point it can be sold at farmer's markets. Or, if the caregiver is just sharing the crop from his/her own 12 plants, and not growing separate plants for the patient, an agreed amount per month to be provided to the patient (1oz/mo, 2oz/mo, whatever). The caregiver has X years of growing experience, X setup, can produce an estimated X amount per month of X quality, X strains are available. Yadda yadda...