As far as metal it needs, is just a driver door, driver fender, and front grille, all the other panels are in good shape including floors and trunk.
I don't see how a motor rebuild is 4k. I estimate it at 2k
And a transmission rebuild I can do myself. Or for the time being I can throw a sbc and th350 trans in it just to get it on the road, which I have sitting in my garage. Tires and wheels about 1k. I can rebuild the rear end.
And paint can wait. Wire harness $500.

I have seen worse cars than this be restored so I know it can be done