(a) It is unlawful for any teacher, supervisor, commissioner, director of schools, member of a board of education or other school officer in the public schools to have any pecuniary interest, directly or indirectly, in supplying books, maps, school furniture or apparatus to the public schools of the state, or to act as agent for any author, publisher, bookseller or dealer in such school furniture or apparatus on promise of reward for the person's influence in recommending or procuring the use of any book, map, school apparatus or furniture of any kind, in any public school; provided, that nothing in this section shall be construed to include authors of books.
(b) Nothing in this section shall preclude a spouse or family member of a principal, teacher or other school administrative employee from participating in business transactions with the school system where a sealed competitive bid system is used; provided, that the principal, teacher or other school administrative employee does not have discretion in the selection of bids or specifications.