Revenue bonds issued under the provisions of this act N.M. Stat. Ann. § 5-3-1 to 5-3-8 shall bear interest at not to exceed four and one-half (4 ½) per cent per annum, payable annually or semiannually, shall be payable at the option of such municipality at the end of ten years from date thereof; and due by their terms in not more than twenty years from date thereof; as determined by the municipality; shall be serial in form and maturity and numbered from one upward, consecutively, and shall be sold for cash, at not less than par, and at either public or private sale.