The most reasonably priced component used on the Cbr400rr 1989 (k) Japanese Domestic / Nc23-109 Gasket Kit B is the Washer,plug,drain 12.
Parts such as the Gasket Kit B: Wash,sealing,20mm, O-ring,17x3, Washer,sealing,6., O-ring,14.8x2.2 are included in the Cbr400rr 1989 (k) Japanese Domestic / Nc23-109 Gasket Kit B parts fiche.
Of all the components used in this assembly the Gasket Kit B (mca) is the most expensive.