The component with the lowest price in the GEARSHIFT DRUM schematic is the Circlip,ex,14.
Parts such as the Gearshift Drum: Spg Pawl Plunger, Roller,4x8, Bolt,flange,6x45, Pin,shifter are included in the Cbr600f Hurricane 1989 (k) France / Kph Yb Gearshift Drum parts fiche.
The most expensive part in this assembly is the Drum Comp,gear Sh.