Here's a couple of questions. I'd expect a range of different answers as we all have different experiences in hi-fi, different AB demos that we've attended.
1. If you take 2 x components at random, how often will the more expensive component sound better, and how often will the less expensive component sound equally good or better? For the purpose of this question, you might like to use the original retail price, with any adjustmens for inflation using this:
http://www.wolfbane.com/rpi.htm
2. If you were to cherry pick an inexpensive or not too expensive component, what percentage chance would you give it for sounding equally good or better than a more expensive component picked at random?
My highly estimated answers to those questions would be:
1. More expensive sounds better 70% of the time. Cheaper sounds equally good or better 30% of the time. BTW if we were to take random components and look at their weight, I'd estimate heavier would sound better 75% of the time.
2. Cherry picked "reasonably priced" sounds equally good or better 85% of the time.
If hi-fi were a boardgame, it'd be a game mostly of skill, with some luck to it.