Even at that give away price, I don't think they will sell many.
The E23 is not a popular choice for a restoration.
There were 285,000 made
You would never get your money back at sales time.
Those that want a nice one can still find a low mileage original or, at a minimum, a rust free one.
IMHO, it would have to be a rich guy restoring a rusty hulk that has a bunch of sentimental value.
I toured the 5 series BMW plant in Dingolfing in the 90s when I owned an E34. The "bodies in white" waiting for assembly looked just like the one pictured in the W&N ad.
It is VERY cool, however, that W&N chose to find warehouse space to save them. You never know...