Contractors shall arrange for the exchange of items, allowing pupils or boards of education an exchange price as liberal as granted on the same items to any city, county, or state in the United States, like conditions prevailing. The exchange privilege shall extend through one entire school year. Nothing in this article prevents the use of supplementary instructional resources, print or electronic, provided they do not displace the adopted instructional resources, nor the use of more advanced items in such schools as may be ready for the same. The state Board of Education is authorized to approve any depository or depositories, either public or private, to serve any county or several counties, whose purpose includes, but is not limited to, offering the savings and services generally associated with local distribution of instructional resources or electronic instructional resources that are not web-based, or any combination thereof, to counties and schools.