1973 Dart Sport 340 4 speed.......how rare? Value?

Off the top of my head, High end $15,000. Low end $10,000. Probably more to the low end as it is going to need some body paint work.

With a paint job, definitely Higher end of my price guess. I am going by what I think its worth in my area. (Northeast)
it is a 340 car, that makes it a High performance factory car, a piece of history none the less. If you are looking to flip as is, start at 10 K, but be expected to be talked down. But don't go too far down, I think $7500 would be as low as Id go, and it would hurt to let it go at that. Of course I don't know what you have into it. If it runs and lays bone (rubber) that is a selling point for a hot rod...:)