The governing body may sell any or all of the bonds authorized under this chapter in such manner and for such price as it may determine to be for the best interest of the unit. Any or all of the bonds authorized under this chapter may be exchanged for the bonds to be refunded thereby or the evidences of indebtedness to be funded thereby, including bonds not matured or redeemable if the holder thereof be willing to surrender the same for retirement. Additional bonds may be authorized and sold under § 9-11-103(3), in an amount sufficient to pay:
(1) Any redemption premium on bonds refunded; and
(2) If such funding or refunding bonds shall be sold or delivered in exchange at a discount, the amount of such discount.