I was in high school in the early 80s when most of these cars were 10-15 years old, or right at the bottom of their value. They were old clunkers that people gave to kids so we could drive the wheels off of them. On any given day, there were easily 20-25 Mustangs of various vintages in the parking lot. There were maybe a dozen Camaros, and all of the mopars could be counted on one hand. In my group of closest friends, there were 4 Mustangs, 2 Chevelles, 2 Camaros, and my lone Road Runner.
Interstingly enough, the Barracuda came to market before the Mustang. But stodgy styling and the association to the Valiant line (IE little old ladies) compared to the cleaner Mustang design and advertising towards the youth market, put Plymouth at a disadvantage right from the start. Yeah Mopar made up for it 5 years later, but by then the writing was on the wall and the era had peaked and was going to tank before Chrysler could capitlize on it.
In absolute numbers, there were more Challengers made than E body Barracudas. Is this part of what attracts buyers to Cudas and drives their cost higher, or is it that it more closely resembles the Camaro than a Challenger does, I don't know but I'm sure we all have an opinoin of that. In the limited run, pedigreed cars like Hemis and 6 packs, values will always be higher, regardless of model. But in the more pedestrian /6, 318, and 383 cars, the Challengers will typically be priced lower than a comparable Barracuda.
Restoration costs, on the other hand, will be about the same between a Cuda and Challenger, which will always be higher than the equivilent Camaro or Mustang. That is just simple economics.
