Unless otherwise provided by law, all contracts for purchases of health and human services shall be awarded by competitive purchase of services pursuant to section 103F-402, except as provided in:
(1) Section 103F-403 (Restrictive purchase of services);
(2) Section 103F-404 (Treatment purchase of services);
(3) Section 103F-405 (Small purchases); and
(4) Section 103F-406 (Crisis purchase of services).