Every contract made by the Board with the publisher of any school textbook on the State-adopted list shall be deemed to have written therein a condition providing that if that publisher, during the life of his contract with this State, contracts with any other governmental unit or places that textbook on sale anywhere in the United States for a price less than that stipulated in his contract with the State of North Carolina, the publisher shall immediately furnish that textbook to this State at a price not greater than that for which the book is furnished, sold, or placed on sale anywhere else in the nation. (1955, c. 1372, art. 24, s. 10; 1969, c. 519, s. 1; 1981, c. 423, s. 1.)