Has the manufacturing of wines undergone as much technological development as the making of speakers? It seems on principle erroneous to expect one industry to precisely mirror another.
You are speaking of a situation where potentially a 4-6% investment might yield a similar result (perceptually) to a competing product that is approximately 25 times more costly. I cannot say that I know of many examples of this in audio speakers. Most vintage speakers I have heard have significant limitations (Man, most NEW models have severe limitations! Just look at how MANY floor standing speakers are not even close to true full range operation!). Most new ones have been built to a price point and as such will not yield the performance "bonus" that you seek - a case of "you get what you pay for."
The only speaker I encountered that may fit closer to this criteria of "2 Buck Chuck" sound is the Best Buy Insigina. Much hilarity and mocking has been seen regarding this speaker, but it's amazingly good for a "dirt cheap" pair. Is it true HiFi quality, not really as one can easily hear shortcomings in it. However, it is a great option for those wanting an inexpensive Mid-Fi rig. But even with this example, while on the one hand you might find outrageously priced monitors which don't easily outperform the Insiginia, on the other you can easily find offerings which trounce it at say 20-25 times the price.
Even the venerable Quads are not so close to the price quotient you are asking about. So, my answer would be "no", as the situation with audio, particularly speakers, is not transferable from vinters. I had spent many years privately looking for the "best of the least expensive" in audio and found the ratio of excellence and price performance of a low cost component compared to a higher priced one to be somewhere in the range of 30%-50% of the higher priced component's cost. In other words, it would take double or in extremely rare cases, triple the money to best the truly exceptional performance of an that speaker/component.
But investing only 4-6% and achieving similar results? I don't think so. Of course, we are dealing with a question of perception, similar to perceiving the taste of a wine. As a result, some may feel that vastly more economical speakers can sound "just as good" as contemporary offerings at a fraction of the price. This may be more the case with high efficiency speakers, but I'm definitely not seeing it with larger floor standing speakers. Trust me, if I could get anywhere near that kind of "return on my money" in this hobby, I'd be all over it! Factor in the time commitment (time is indeed worth plenty of money for many of us) needed for DIY and its potential advantage diminishes as well, in some cases for a crap shoot result.
BTW, you may be assuming similar speaker configurations, and that would indeed potentially benefit from blind testing. However, without such constraints the differences between speakers is so radical in many cases, and the resultant sound so different, that blind testing would be unnecessary to establish the performance advantages of one over the other - a very significant difference between wines and speakers.
