The component with the lowest price in the TRANSMISSION schematic is the Bolt,flange,6x16.
Some items from this specific schematic: Washer,23x35x2, Collar,23x30x17.5, B/brg N/rad N/com, Gear,c-3.
With a quantity of five pieces, the Bolt,flange,6x20 is the most used part in the TRANSMISSION diagram.