It appears I stand corrected. I could only find one source, and not really a definitive one, that backs up the higher cost for a Hemi over a 440-6 for the old E-Body Mopars. Not sure where or how I formed my earlier understanding, but alas, I apparently was mistaken. My bad.

But I do know what you mean about the hemi vs. other engines in terms of performance. In my case, I restored my Cuda 340 a few years back. Bumped the CR up from 8.5:1 to 10:1, added a mild competition cam, replaced the 1972 valves with larger ones (like those from 1970), added headers, and performance intake manifold. As a result, the response of my 340 is absolutely incredible. At just about any speed/RPM, a quick punch on the accelerator results in the car jerking forward, even at highway speeds. My new SRT8 with 6.1L Hemi doesn't do that until the RPMs are "up." But, with all that said, once that Hemi is turned loose, it's like a rocket. Better rest your head on the headrest as it's going to wind up there anyway...