The department shall collect fees for registrations as follows:
I. Flat Fees:
(a) For each trailer or semi-trailer upon which is permanently mounted a power substation or transformer and associated equipment used for standby or emergency purposes in public service-$5.
(b) For motorized locomotives of the American Legion-$5.
(c) For each dealer's, motorcycle dealer's, moped dealer's, or utility dealer's temporary plate-$1 each.
II. All unused temporary plates issued pursuant to paragraph I, which are returned by a bona fide dealer to the division shall be refundable at the rate of $1 each; except that temporary plates purchased at the rate of $.50 each shall be refundable at the rate of $.50 each.
[Paragraph III effective until January 1