That's like saying why should a 318 Coronet be worth less than a Sixpack Superbee? There were more A-bodies built because they were cheap economy commuter cars. E-bodies were flashy expensive sporty cars. More people wanted them, but couldn't afford them. People at work talk about getting back from Vietnam back then and how much money they were making and what they could afford. Now they make much more money and could afford the cars they wanted back then, and that drives the price up. They don't dream about the '72 slant six Duster that got away. All the better for those that do like A-bodies. I got a '69 smallblock Swinger from my neighbor for $2000. Around 90,000 miles, from Arizona, zero rust, original canary yellow paint like that Craigslist Dart, but bad seat covers. $16,000 is incredibly high. Looks like it's in good original condition, and only 16,000 miles, but it doesn't do much for the excitement factor, and that's why it's not worth that much.