I'll buy multidisk clutch parts all day long. The rest of the transmission, not so much.
Being in the US, I'll also pay decent money for RHD clutch housings, particularly early ones. It's cheaper than having to mail them from Australia or NZ (which I've done).
The rest, have to admit, is pretty much true per the above comments. I did pay $400 for a nice December 1927 manufacture block for my RHD Phaeton. And then paid $4600 to have it rebuilt.
But it's the correct engine for my car, so...that's how this works sometimes.