I continue to press for a firm and clear distinction in discussions between (1) “subjective” and (2) psychoacoustics because these are very different things.
Audio “subjective” is associated with casual observations, weird analyses, poetic writing, arbitrary personal preferences, disguised biases (as you say, paying more for gear can equate to liking it more), and whatnot. If one describes sound quality as “romantic” or “cloying” or “musical” they likely fall into this camp. If one focuses on built quality and style one may fall into this camp during non-blind listening.
Psychoacoustics is one branch of the biological and cognitive sciences. While it is certainly less precise than the hard sciences (i.e., physics, chemistry, astronomy, etc.), these fields are highly ordered and predictable. Most bio-psych measurements fall onto bell curve or normal distribution across people, whereby most people are similar and a few are distinct outliers. To compare analytical precision to flowers, if chemistry is a field of cookie-cutter daisies or poppies, humans are a field of roses. There are red ones, yellow ones, white ones, pink ones, ones with many petals and others with just five petals, but they generally smell like roses and have thorns. They all die off in the winter and grow back in the spring. Some human subpopulations with similar biology/genetics may have largely similar audio preferences too, and that’s a fully testable idea.
Beyond the bell curves of hearing and perception, humans are highly affected by their lifecycles. We learn a lot as we grow, and development in each perceptual and cognitive domain differs. Small children may have perfect 20/20 biological vision but not understand the cognitive metaphorical meaning of a political cartoon until becoming an experienced adult. Writers can improve their skills until their 50s or even 60s, even though some teenagers have very large vocabularies. As such, the ability to hear musical qualities could continue to improve to some point between age 18 and 60, and this is testable too.
Aging also harms perception, whereby general cognitive problem solving (e.g., executive function) starts to decline around age 50 and the decline is steeper by age 60 to 65 (i.e., a large group of big spenders on audio equipment). Dementia becomes more common, and older adults are known to enter a “second childhood” of impulses and pleasure. At the same time, hearing high frequencies falls off and thereby people tend to lose the ability to discern what makes any given piece of gear different from the next. And audio shows thereby have many bright and piercing demo systems.
I fear that most audio hobbyists gravitate to easy but largely irrelevant black-and-white answers (i.e., electrical test gear, and commonly known as “objective” measurements), when the primary and most important distinguishing factors are psychoacoustic and fuzzier. But these are highly predictable and a 3rd way that involves neither the standard usage of “objective” nor “subjective” factors.