The guy I sold my 74 SD to (in late '07 I think it was) was here yesterday. He thinks he may get it finished at around $60,000 but I'd be shocked if he does it under 70. Mine was completely rotten but matching numbers. Easier to buy a finished car for the same price and it will always be worth more if it's always been a rust free car.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)