You must really love this car to be preared to spend that kind of money. As OK points out, if the brake and fuel lines are rusted that bad, there is a whole lot more that will need replacing now or soon.
I sold a 1988 Caprice two years ago; this car had never been driven in a corrosive environment, and the next owner could drive it without fear. Had it needed the kind of work you describe, I would have SCRAPPED it!