Each person, firm or corporation engaged in operating a sawmill, heading mill or stave mill shall pay a privilege tax according to capacity as follows: Those having a capacity of 5,000 feet or less per day, $10; those having a capacity of more than 5,000 and not exceeding 10,000 feet per day, $25; those having a capacity of more than 10,000 and not exceeding 25,000 feet per day, $50; those having a capacity of more than 25,000 feet and not exceeding 50,000 feet per day, $100; those having a capacity of more than 50,000 feet per day and not over 100,000, $200; those having a capacity of 100,000 and not over 150,000, $300; those having a capacity of more than 150,000 and not more than 200,000, $400; and those having a capacity of more than 200,000 feet, $500. Only one state license shall be paid by the operator or owner of any sawmill.