A municipality may not sell or enter any contract for the sale of any issue of its bonds authorized by this chapter in an amount exceeding one million dollars, for whatever purpose issued, without first advertising for bids in the manner prescribed by section 21-03-26, except as provided in section 21-03-30, and except that bonds issued under the authorization of subdivision g of subsection 2 of section 21-03-06 with the consent of the warrant holders, may be exchanged for matured warrants or matured interest coupons of warrants of the special improvement fund having the deficiency on account of which such bonds are being issued, without such advertising. The par value and accrued interest of the bonds so delivered may not exceed the par value and accrued interest of the warrants and interest coupons, and accrued interest thereon, for which they are exchanged.