Each person compiling, selling, or offering for sale directories shall pay to the state license taxes as follows: For each city or town of 100,000 inhabitants or over, $150; in cities or towns of 50,000 and less than 100,000 inhabitants, $75; in cities or towns of 20,000 and less than 50,000 inhabitants, $50; in cities and towns of less than 20,000 inhabitants, $15; provided, that this section shall not apply to directories issued by any person in connection with or as a part of a business for which a general license tax is provided.