That 1984 trek doesnt owe you anything. You have had many many years of enjoyment from it. Unless you are financially strapped (and it cant be so bad otherwise it wouldnt be an option at all) Id say go for it!!

Im not saying spend 6k on a super bike but 2k will put you on a beautiful new ride that you will be proud to show-off to all your buddies.

Do you own a car??? is it 25 years old??? of course not! times change, things wear out and need/deserve to be replaced. consumable items are consumable.

keep your old trek. restore it to its original glory. ride it every now and then. But dont deny yourself the luxury of a shiney new, modern, probably superior, bicycle. yolo.