67.672.  Retailer in area to add tax to purchase price — collection to be based on bracket system. — 1.  In the area of each county in which a tourism sales tax has been imposed in the manner provided by sections 67.671 to 67.685, every retailer within such area, except as otherwise limited in subsection 4 of section 67.671, but including those located partially within the area, shall add the tax imposed by the provisions of this act^* to his sale price, and this tax shall be a debt of the purchaser to the retailer until paid, and shall be recoverable at law in the same manner as the purchase price.

  2.  In counties imposing a tax under the provisions of sections 67.671 to 67.685, in order to permit sellers required to collect and report the tourism sales tax to collect the amount required to be reported and remitted, but not to change the requirements of reporting or remitting the tax, or to serve as a levy of the tax, and in order to avoid fractions of pennies, the governing body may authorize the use of a bracket system similar to that authorized by the provisions of section 144.285 and notwithstanding the provisions of that section, this new bracket system shall be used where this tax is imposed and shall apply to all taxable transactions.