Ariz. Rev. Stat. § 35-457
A. Any or all of the bonds may be sold at public sale or through an online bidding process in a manner prescribed by the governing body or board that includes the following:
D. The bonds may be sold below, at or above par. If an issue of bonds is sold below par, the aggregate amount of discount plus interest to be paid on the bonds must not exceed the amount of interest that would be payable on the bonds over the maturity schedule prescribed by the governing body at the maximum rate set out in the resolution calling the election at which the bonds were voted. The amount of net premium associated with a bond issue may be used only for one or more of the following:
3. For any other purpose, if the political subdivision has voter authorization and available capacity under its debt limitations and the amount of net premium used for such purpose will reduce in an equal amount both:
F. For the purposes of this section: