why not get it running and enjoy it? i can tell already you're one of those people that is going to think the thing is worth a kajillion dollars so save yourself the headache of selling it and just keep it!
non running 400-600 to the right person
running 800 max
cleaned up, new tires and tubes, chain, running perfect and totally dialed in maybe max of 1000-1200 bucks
i'd fix it up, ride it around, see how you like it. might bring back some great memories.