Anyone who has watching Danny Richie from GR-Research has seen first hand that spending more money on audio does NOT ALWAYS equal better performance or even better parts.
I think it’s naive to think that it does, but it is a natural inclination to think that way because often times spending more money DOES bring better performance. Having said that, there are many factors which would contribute to better sound with synergy being one, individual hearing ability as well as having a trained ear as two more, the "I got more expensive new gear so it must be better" factor being another and so may others etc, etc.
I think experience would be the far more important factor as well as knowing one’s self. Taste in sound is another important factor and so is the degree of arrogance or objectivity and open-mindedness (internally) one has to recognize when listening to gear.