Some items from this specific schematic: Washer, Plate (30x), Axle, Main (15t), Gear, 5th Wheel, Gear, 6th Pinion.
This Axle, Main (15t) is the most expensive of the items that make up this Transmission assembly.
The lowest price component in this Transmission parts-list fiche is the Screw, Countersunk(4jt).