The lowest price component in this Taillight parts-list fiche is the Bulb.
Parts such as the Taillight: Lens, Taillight, Reflector, Rear 1, Gasket, Tail Lens (nas), Ybs66-5 Washer, Plain are included in the Tzr125l 1989 3pb1 France 293pa-351f1 Taillight parts fiche.
With two applications this Bulb is the most specified part.