For the purpose of section 308, “net cost” means:

    (a) For a community mental health services program expenditures eligible for state financial support and approved by the department that are not otherwise paid for by federal funds, state funds, or reimbursements from persons and insurers who are financially liable for the cost of services.

    (b) Except as provided in subdivision (a), the total of all community mental health services program expenditures eligible for state financial support and approved by the department that are not otherwise paid for by federal funds or state funds.