The Gasket(6.2x11x1) (nas) is the cheapest item from this partsfiche.
The Crankcase Cover assembly is constructed from several parts from which the Cover, Clutch is the most expensive.
This schematic depicts all components used in the Gp125 1983 (d) (e02 E04 E17 E18 E21 E22 E41) Crankcase Cover partslist.