If you are asking why the engines cost more, I think Larry Shepard's Engiine Manual explains it better than I can.
Actually, Mopar engines cost less in the long run based on reliability and power for dollars.
If you are asking why the CARS cost "so much", I'm sure there are several reasons.
Hype being at the top of the list. (Think Barrett Jackson and GG)
Another thing is that those that own "the cars" either don't want or don't to have sell them for less than they are asking for them.
(Simple)
But I think (think) one of the main reasons is fairly obvious.
Stay with me here.
This is a site that I go to for laughs on hyped ads.
Please note that this one dealer has no less that 14 (fourteen) Mopars for listed for sale on his own site.
And how many dealers are like this out there?
http://www.cars-on-line.com/27921.html
If that isn't "cornering the market" I don't know what is.
The cars are being held hostage.
Yes, I blame dealers for the prices.
I say "blame".
Maybe that isn't the right word?
Quite possibly some think high prices are a good thing.
Good for the hobby?
You be the judge.
But I will tell you that I have told dealers to take a flying when they have tried to buy cars from me for less than I was asking just so they could make money.
And that was when nice 340 Challengers were going for 7K.
I know. I was there. It was pleasant.