I have a complete roof off of a 1973 Plymouth Duster on eBay with a buy it now price of $125. You could get it for less.
Plymouth Duster, Dodge Demon, Dodge Dart Sport, Mopar A Body, Roof, Vinyl Top
It will fit 1970 - 1976 Plymouth Dusters and 1971 - 1976 Dodge Demon / Dodge Dart Sport model...