bretmcee,
There is no doubt that room has a lot to do with final performance. I suspect that the world's most expensive speakers may not sound as the world's best speakers once placed in the mountain cave, but overall the price does follow "quality". There may be items that are slightly better ("better" being "I like them more") while slightly less expensive than others. Still, this thread is full of generalizations and not many examples.
By the way, this definition may have, a fatal flaw...
"...to increase the enjoyment gained from the reproduction of sound in ones own private listening space."
It would exclude anyone who listens, or tries to improve something, anywhere else but in own private listening space. Concession should be made for headphone listening in public transport, I guess.
Also, do not forget that just owning a pair of speakers, not a Bose radio but separate pair of speakers, is a luxury in many/most of the people's minds. It is, to some extent, a wasteful indulgence. A hobby of those spoiled few who do not care about money. Spending $500 for a pair of speakers is about the same as spending $500 000. Unnecessary in a grand scheme of things. Number is different, but anything is too much anyway. Add prices of all three pairs of your speakers (or how many more you have) and you will get the actual price of your "speakers" for the purpose of "cheap vs. expensive" argument and socio-economic debate raging here.