All bonds, except revenue bonds, issued under this chapter shall be sold by the governing body at not less than 95 percent of their par value together with accrued interest from the date of the bonds to the date upon which they are delivered and paid for; provided, however, that towns and cities having a population of less than 6,000 may sell such bonds at not less than 90 percent of their par value and accrued interest to date of delivery; provided further, that funding and refunding bonds may be exchanged for outstanding obligations as provided in subsection (b) of Section 11-81-11.