No district shall become indebted for an amount that may not be payable from ninety percent of twenty times the current annual maximum tax levy as authorized by section 11-28.3-09. Within the limits herein authorized, the district may borrow money and issue appropriate evidence of indebtedness. No evidence of indebtedness issued under the provisions of this chapter and sold privately shall bear interest at a rate or rates and be sold at a price resulting in an average annual net interest cost higher than eight percent. There shall be no interest rate ceiling on those issues sold at public sale. No evidence of indebtedness issued under the provisions of this chapter shall be sold for less than ninety-eight percent of par value plus accrued interest, if any interest has accrued as of the date of delivery thereof.