Before doing business under the provisions of this chapter each licensee shall file with the Commissioner of Assessments and Licenses, his, her or its complete schedule of prices by the hour for household goods and personal effects, and by mileage for pianos, not in excess of the charges established by Section 679.14, and a copy of the same shall be conspicuously posted and kept in the business offices of the licensee. However, such schedule of prices by the hour shall set forth the point at which such time shall commence and end and how much time shall be deducted for lunch.