what is the most Desirable A body line

Tough to compare cars with options not available in other years. Like a 68 383 GTS convertible to a 70 318 Duster.

The original question said body line so I would take that as a /6 2dr body style that was available in every body line. Duster/Demons are fastback (VL29 & LL29) versions of Valiant/Dart . So comparable to 67-69 Barracuda fastback.

Right now, Demons seem to be the hot a-body builder. Here’s my opinion on current desirability $$$ if all were /6 auto cars in same condition.

Highest selling $$ on top.

71 Demon (fastback A-body)
68 Barracuda Fastback
68 Dart
69 Dart
71 Duster (fastback)
70 Duster (fastback)

69 Barracuda fastback
67 Barracuda fastback
72 Demon (fastback)
72 Duster (fastback)

70 Dart
67 Dart
68 Barracuda coupe
69 Barracuda coupe

67 Barracuda coupe
71 Dart
68 Valiant
69 Valiant
67 Valiant

Within the groupings things get close.