Except as provided in Code Sections 45-10-20 through 45-10-25, employees of hospitals, educational institutions, eleemosynary institutions, penal institutions, and correctional institutions which are under the control and jurisdiction of a state department or the Board of Regents of the University System of Georgia shall be entitled to obtain goods and services in the same manner and under the same procedure used in obtaining such goods and services through such hospitals and institutions and the laws of this state relating to purchasing contrary thereto shall not apply to such employees; provided, however, that no employee shall be permitted to make any single purchase of goods or services in excess of $50.00, except medical and dental services only; and in no event shall any employee obtain goods or services for any person except for himself or members of his immediate family.