If, after determining the objections made to the commissioners’ report, the court shall find that the estimated costs of works and improvements as reported by the board of commissioners, or as amended by the court, exceed the estimated benefits, the court shall then render its decree, declaring the incorporation of the district to be dissolved as soon as all costs incurred, which shall include court costs and all obligations and expenses incurred in behalf of the district by the board of supervisors shall have been paid, and if the uniform tax levied under the provisions of section 242.430 be found insufficient to pay all such costs, the board of supervisors shall make such additional uniform tax levies as will be necessary to pay such deficiency; provided, that in estimating the cost of constructing the works and improvements of the district the amount of interest that might accrue upon bonds that may be issued by the board of supervisors under the provisions of sections 242.010 to 242.690 shall not be considered as a part of the cost of construction.