Should I rescue this? '66 Dart 4-door

Bargain for $500 if you can, then throw a couple hundred in parts for a decent runner or part it out. Like someone said, they all cost the same to restore, so the potential end product is what counts. Not worth restoring unless you know that's the car for you. Don't fool yourself into thinking it'll be a bargain for a restoration because the initial outlay is low.