When to say "too bad to fix"

Too bad to fix in my opinion is when it needs over 50% of the sheet metal replaced from rust especially the rear half.
I would pass it on to somebody that is wanting to do that kind of a major restoration, and in the past i have done just that.
Case in point is a 1969 1/2 Six Pack 4 speed Super Bee post car i sold to a friend of mine years ago.
He has over 50 grand in the body alone and about 80 grand into the car as it sits.
It's beautiful and finished now, but man, that was a lot of work that i wasn't willing to do, and he is very happy with it.........