Prior to the initial authorization of bonds or notes or the issuance of any guaranty to finance any project involving construction or acquisition, the governing body shall obtain realistic cost estimates through actual bids, option agreements or professional estimates from registered architects, professional engineers or other persons qualified by experience. Any local government unit may retain the services of a financial advisor. Costs of preliminary estimates and the fees of financial advisors may, if initially paid by the local government unit, be reimbursed out of the net proceeds of the issue of bonds or notes as a cost of the project.