In order to obtain the facts necessary for the discharge of his duties under this act, the commissioner may use such lawful means as he may deem necessary. He may employ such assistants in making his valuations as may be necessary to complete them in due time. All such persons, whose compensation is not fixed by statute or otherwise determinable by authority of law, shall be paid such reasonable compensation as may be fixed by the commissioner with the approval of the Governor, and within the limits of appropriations available therefor.
N.J.S. § 54:29A-66