The investigation fee charged under RCW 33.28.020 in connection with applications to establish a new savings and loan trust department shall be one thousand dollars. In the event the actual costs of the investigation conducted with respect to a particular application are less than the amount of the fee, such difference between the fee and the actual costs submitted shall be refunded, provided that in no event shall more than five hundred dollars be refunded. Expansion of the originally approved scope of trust business must also be approved by the director by additional application and fee. In the event that actual costs of processing additional applications are less than the amount of the fee, such difference between the fee and the actual cost shall be refunded, provided that in no event shall more than seven hundred dollars be refunded. For the purposes of this section, actual costs include travel and per diem expenses paid to division personnel in connection with the investigation.