Although the image (i.e., end result) might be the same, it is the knowledge of the process involved that would make a difference. And to illustrate what i mean, I have to resort to a gross metaphor: it would be the same as the difference between a waiter spitting into your soup in the kitchen and doing it right in front of you. In other words, knowing that a major manipulation took place would always make it worth less than the one with no manipulation.
It's interesting that you categorise HDR as a "major manipulation". Why do you consider it as so? What's wrong with using the available tools to create the best result possible? Does that inherently make everything the 'straight from the camera' people produce better and more valuable?
How does one determine the veracity of an image though? Are images taken with 10 stop ND filters that show long, wispy, cotton candy-like clouds through captured movement accurate? Can we actually see that with our eyes? Are, for example, Marc Adamus' prints less worthy because he uses Photoshop extensively? Are Tony Kuyper's images less worthy because of his terrific use of luminance masks?
This is, for me anyway, a very interesting conversation. I'm going to post an example and see where it goes.
This image was also taken in Bruce Pen NP on the same trek as the Grotto image. I found the colour of the blue rock to be an interesting contrast to the others around it. And yes, it is actually blue. The first image is a JPEG of the original RAW file out of the camera. The second is the image I ended up with. I don't claim this as a terrific example of good photography. It's more an exercise in trying to illustrate what's 'real' according to what the camera captures and what's 'real' according to our vision. The original is blah and lacks any visual interest at all. The camera simply didn't capture the colours well. The sky was overcast but there was some strong directional light that the camera didn't pick up too well either. I've spent a lot of time with this image over the years since I first took it and have finally come up with something that I'm fairly happy with. It was more an effort at seeing what my processing skills were like than anything else but the final image with the sheen on the rocks and the enhanced colour and contrast is a 'better' image in my view. Putting aside the quality of the photograph from a composition/artistic standpoint, does the final version really have less 'value' because I took some artistic license with the processing? For what it's worth, none of the colour in this image was 'added'. It all comes from working with ACR, Vibrance, H/S, Curves & Levels. Which also is a good indicator of how much may be available in an image that the sensor captures but that doesn't show up in an untouched RAW file.