I can't fathom where he pulled that from, there are MSA log booked, solid, gp4 rally cars available at that price, what a tool.
I follow a lot of their work on fb and youtube and while 24k may seem steep in comparison to others, their work is top notch.
I'm not sure what the quote was for but all their builds seem to follow a similar process.
Sandblast the shell, remove all rot and replace with hand made panels, (they've bought replacement panels for projects and not used them as they're not good enough) all voids are cleaned out and protected from rust, door lines and gaps are matched perfect, bonnet and boot lid get the same treatment.
Shells are then hot zinc sprayed for rust protection followed by numerous coats of underseal/primer etc etc.
The cars they build are on another level and they will last much longer than the cars that rolled off the production line.
I'm not sure if the price is entirely justified as that isn't my trade, but it's easy to see how they get to it with the man hours that must be involved in such a thorough rebuild. Good labour doesn't come cheap.