Each bond issue shall be in the principal amount sufficient, together with other available funds, for the acquisition, construction, and equipment of facilities or the reconstruction, extension, improvement, equipment, or reequipment of facilities, all costs of issuing bonds, the amount necessary for a reserve, if deemed desirable by the authority issuing the bonds, the amount necessary to provide for debt service on the bonds until revenues for the payment of them are available, and any cost of whatever nature necessarily incidental to them.