The Nut,hex 6mm is the lowest priced item on this Cylinder schematic.
Parts such as the Cylinder: Nut,hex 6mm, Dowel,pin,10x16, Cylinder Comp, Gasket,cylinder (nas) are included in the Cb250p 1996 (t) China / Plb Cylinder parts fiche.
The Cylinder assembly is constructed from several parts from which the Cylinder Comp is the most expensive.