Since it is published (school press? ) is a legal publication and can be bought and sold normally. If it is only a school textbook for internal learning, we must first know who the copyright owner of the textbook is. Copyright owners have the right to agree to teach and print a certain amount in schools, but are not allowed to trade in the book market. Even if the copyright owner agrees, it belongs to illegal publishing and illegal book distribution transactions, but sometimes it will expand the scope of use of teaching materials within a certain scope, which does not belong to formal publishing and transactions. It is ok to charge some production costs appropriately. This situation is illegal, but it is not illegal.