Too Rough To Save?

At what point do you say a car is too rusted to save.
1974 Cuda
body media blasted
rust holes on every panel
lots of good parts
When do you say it's not savable?
Yes, there is plenty of parts to sell and I can make money.
I want to know if I should try to save a 74 shell that is
very rusted and how and who would I sell it to.