Not entirely sure what you mean by “a true audiophile hierarchy” and why one would want to establish it. Having said that and since the question deals with audiophiles and “pleasure derived from music”, a simpler and more reliable test would be to put an audiophile in front of two doors each leading to a different room. In one room is a violinist playing Bach (?), or a Blues singer with guitar, or a…..In the other room is a large collection of High End audio gear not even plugged in. Which room does the audiophile go into first and how long does he stay there before going into the other room….if ever?
Not enough information provided in your hypothetical scenario to make a judgement.
If I only have a choice to walk into either room, for that single instance, it would be the live musician. Not even a moments pause to decide.
Not all, or even the majority, of audiophiles fit into the common stereotype, i.e., audiophiles get more enjoyment from the gear, than they do the music.
I am an audiophile. But the music comes first. The gear is only a vehicle for me to enjoy my music.
And to the OP’s question. I would bet at this point in neuroscience, a Functional MRI could get a pretty good idea about the level of activity in the pleasure center, while people listen to music.
And it looks like the NIH has something to say about it.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC58814/