Want to know how much I gave for my '73 Dart Sport?
Nothin'. It was free.
My grandpa bought it new in 1973, and he just held on to it. He put 100,000 miles on it in the first three years, and it's racked up about 200,000 more since then and it was regularly driven until about 1997. He has 3 daughters and none of them were interested in getting this old Dodge handed down to them, and since I was the first grandson, he decided that one day the car would be mine. I grew up loving this car, looking forward to the day I could finally drive it. We used to push it out of the shed every spring and I'd sit in the floor board, push in the clutch, and crank it over while he poured gas down the carb. Cruising down the road, he'd let me shift the 3 speed and 6 year old me thought it was a ton of fun. In 3rd grade I had to do an autobiography and one of my 10 year goals was to save up enough money to fix the car up. I totally forgot about that assignment, but 9 years after I did that the car had new wheels and tires and a fresh coat of paint on it. Now 13 years later, the 225 and 3 speed are in the shop, having been replaced by a 340 that I built, and a 4 speed. If I didn't have this car, I know I wouldn't be as driven as I am. It's changed my life for the better, giving me an outlet to tinker with and to use as motivation to learn new things.
My point is this... These cars aren't worth a whole lot monetarily but they can be worth a ton sentimentally. Your Dart is in pretty great shape considering it's age, and with it's 42 years of family history, I really think you should consider just hanging on to it. It's not costing you a fortune to keep around. Tinker with it, get the family involved, make some memories with it. The car has lots of potential! Disc brakes, and a tune up could turn this thing into a great economical antique cruising machine! You never know, one day you could pass it down to someone and they'll do to it what I've done to mine. Or they'll restore it to stock, or maybe even leave it as-is and just enjoy driving it.
Here are a few pictures of mine over the past 5 years. These old Darts can look pretty cool if you show them some love.