A financing agreement must provide that the state may, at the expiration of the original or any extended term, purchase the project at a stated price, which must be the balance of the total project cost not amortized by the payments previously made by the state. The financing agreement must provide that if the option to purchase the project has been exercised or if the financing agreement has been extended for the full number of years which it may be extended, and all payments provided for in the financing agreement have been made and all project costs have been paid, the commission shall convey its interest in the project to the lessee.