The most reasonably priced component used on the Pk50 Wallaroo 1999 (x) Netherlands / Mp Std Crankcase is the Bolt,flange,sh,6x25.
A sample from the products for the Crankcase include: O-ring,20.6x1.9, Bolt,flange,sh,6x25, Bolt,flange,sh,6x40, Oil Seal,17x30x5.
Of all the components used in this assembly the Crank Case Left is the most expensive.