S.C. Code Ann. § 59-31-520: Continuance of contracts with publishers.

At the expiration of any contract between the State and the publisher of any textbook, the State Board of Education, upon satisfactory agreement being had with such publisher, may continue the contract for any such textbook, or the latest editions thereof, for an indefinite period which may be terminated either by the State Board of Education or the publisher upon ninety days' notice. The Board may extend contracts at different prices from those of the original contracts.