(a) For the 1989-90 school year, the commissioner shall establish interim tuition rates for approved preschool special education programs and services, including evaluation components, subject to the approval of the Director of the Budget.

(b) The interim rates established by the commissioner for preschool special education programs and services in existence on June 30, 1989, shall be based upon the tuition rate in effect for each such approved preschool education program or service on June 30, 1989, subject to the approval of the Director of the Budget.

(c) The commissioner shall establish interim tuition rates for newly approved preschool special education programs or services for which a tuition rate did not exist as of June 30, 1989, based on a budget submitted by the persons operating the approved preschool special education programs or services, subject to approval by the Director of the Budget.

(d) Such interim rates, as calculated pursuant to subdivision (b) or (c) of this section shall be adjusted, to the extent the commissioner deems it necessary and reasonable, subject to the approval of the Director of the Budget.