The component with the lowest price in the PROPELLER SHAFT/FINAL DRIVE GEAR schematic is the Washer.
Some items from this specific schematic: O Ring(d:1.9,id:61.6), Stopper,final Drive Bearing, Bolt,stud, Plate,bearing Stopper.
The Propeller Shaft/final Drive Gear assembly is constructed from several parts from which the Gear & Case Set,final Bevel is the most expensive.