All wiring harnesses and electronics, thats the real pain in the ass. Every computer and wiring harness has to probably be replaced and re-ran. Electronic gremlins are no fun. Huge labor cost to get at everything for this.What would there be to fix on the tub, like what is damaged on it?
Considering how low that car is, its not even in very deep water. I'd wager the engine would be fine with being rebuilt. Everything else though yeah would be toast.
Heck the interior is pretty sparse in those. Replace some wiring, the small screens, the few pieces of alcantara and you'd be done - everything else is solid carbon.
Even if its written off, someone will 100% buy it from the auction.