B20 spares - 2 refurbed heads, 2 each of intake/exhaust pipes, in France

[Parisien]

Things are getting a bit out of hand price wise?!

https://www.leboncoin.fr/equipement_auto/1072761383.htm?ca=11_s

"Selling ​​2 proven cylinder heads and surfaced (invoice), 2 intake and exhaust pipes for lancia aurelia B20 6th series
-Price of 2 cylinder heads 6000 eu
-prix of the 2 intake pipes 500 eu
-prix of the 2 exhaust pipes 1500 eu"

P

[chriswgawne]

Whilst on the face of it these prices seem high, the reality is that original Aurelia engine components are now > 60 years old and cylinder heads and inlet manifolds are becoming prone now to major corrosion and porosity.
Only this week I have heard of an Aurelia owner with an apparently lovely car whose engine has failed spectacularly due to porous inlet manifolds. He is facing a very expensive total engine rebuild and will almost certainly want to source good usable replacement cylinder heads and inlet manifolds. This is easier said than done as such things are now in short supply.
Porous and corroded castings can of course be repaired and tested but at what cost? And I would have thought it was highly unlikely that anyone will make new cylinder heads or inlet manifolds until the value of the cars themselves has risen significantly (which may never happen).
So how much out of hand are these prices actually? (assuming the components for sale here are in good usable condition of course).
Chris