The ordinance may provide that the estimated cost stated therein of the public improvements includes any or all of the following:

1. (a) Legal or other fees incidental to or connected with the authorization, issuance and sale of the bonds.
2. (b) The costs of printing the bonds and other costs and expenses incidental to or connected with the authorization, issuance and sale of the bonds.

3. (c) If the public improvements are revenue-producing public works, bond interest estimated to accrue during the construction period and for a period of not to exceed 12 months after completion of construction.

   If such statement is made, the proceeds of the sale of the bonds may be used to pay such of the foregoing as are stated in the ordinance.

   This section shall not be construed to authorize a city to use the proceeds of the sale of bonds for a purpose for which it could not use its general fund.