Agree with you 100%!

I was explaining to my wife my amusement at that seller...

He doesn't sell a NOS 1st generation Campy Rally rear deraileur for $175-$200
NOOooooo
The outer cage plate is BIN for $95! (as is the inner cage plate)
The attachment bolt is BIN $65
Reach adjustment screws..$45
Rally body..$125
Internal spring
Pulleys
Cable anchor bolt

You get the idea

(and this's purely my own humble opinion btw)

But he gets 5 Bills for the deraileur in the long run, and all the silly saps in need of "just that one little piece" are happy as clams. (me included)

And that kind of meticulosity is never in a hurry!

I'll be interested to know the new venue, I just need this one little part to finish the....