Section 25A. The state purchasing agent may provide for the transfer of supplies and equipment purchased from state appropriations from one state agency to another when, in his opinion, such transfer is for the best interests of the commonwealth, and may provide for the making of suitable adjustments on the books of account of the commonwealth of such transfer. He shall also have authority to approve the amount or quantities of all supplies and materials purchased by state agencies, notwithstanding that such agency has conformed to the regulations relative to such purchases and that an appropriation is available therefor. In case an application by a state agency is not approved by the state purchasing agent, such agency may appeal in writing to the commissioner, whose decision shall be final.