Ducati tolerances

[Butcher]

So building a bike with tighter tolerances isn't more costly than one with looser tolerances?

Building anything in a machine shop environment with tighter tolerances is more expensive for the manufacturer. 

Let me give a quick, general example: 

You're cutting a solid piece of steel rod in a machine shop to provide to a manufacturer.  You are making production parts, running hundreds or thousands of them over a couple of days. 

The machine is setup, and let's just say that it saws the rods to length.

Things...vary.  Some rods are ten inches long.  Some rods are 10.1 inches long, some are 10.012 inches long.  Etc.

If the manufacturer that spec'd the parts (on the engineering drawing) called out a tolerance of + / - .001, then that means every rod that doesn't meet this spec cannot be used.  Often, these are complicated machined parts and must be scrapped. (like if the rod it too short) Thrown away.  For every part the machinist throws away, costs go up for the machine shop.  Thus, the bill to the manufacturer for their production parts goes up as well.

The manufacturer raises the retail price to compensate for increased costs.  The consumer pays a higher price. 

So......

--> The tighter the tolerance, the more expensive the end product, pretty much in any case.