Parts such as the F-28: Wire,a,water, Pipe Comp,r Water, Bolt,flange,6x40, Nut,flange,6mm are included in the Cn250 Fusion 1988 (l) Japan Mf02-120 F-28 parts fiche.
The component with the lowest price in the F-28 schematic is the Nut,flange,6mm.
Of all the components used in this assembly the Pipe Comp,r Water is the most expensive.