(a)(1) It shall be unlawful for any full-time public official who has state-wide powers, for himself or on behalf of any business, or for any business in which such public official or member of his family has a substantial interest to transact any business with any agency.

(2) It shall be unlawful for any public official who has limited powers, for himself or on behalf of any business, or for any business in which such public official or member of his family has a substantial interest to transact any business with the agency for which such public official serves.

(b) The provisions of paragraph (1) of subsection (a) of this Code section shall not apply to:

(1) Any transaction made pursuant to sealed competitive bids;

(2) Any transaction when the amount of a single transaction does not exceed $250.00 and when the aggregate of all such transactions does not exceed $9,000.00 per calendar year; and

(3) Any transaction involving the lease of real property to or from any agency if such transaction has been approved by the State Properties Commission or the Space Management Division of the Department of Administrative Services.

(c) Any person who knowingly violates subsection (a) of this Code section shall be subject to the penalties provided for in Code Section 45-10-28.