Orpheus: When the OP went from his original question to 25K, that changed everything, because that’s way past "diminishing returns"
This is a fine point, orpheus. You presented your perspective on the question he raised. For you, $25k is already past the point of diminishing returns. Okay, that’s one experience and value proposition. It wouldn’t be mine; it’s clearly not the OP’s.
More importantly, though, is the BASIS on which we each evaluate and determine the point of diminishing return.
There clearly is no absolute monetary figure. As in so much of the investment we each make in our audio systems, we are dealing with: 1) what differences do we hear, 2) do we consider the differences material GIVEN OUR LISTENING PRIORITIES (which are different for each of us), 3) how much enjoyment do we anticipate from that difference we’ve identified, 4) what discretionary budget do we have available, and 5) to what alternate use would we put that discretionary budget and how do we value that alternate use?
To simply state a monetary figure just means that FOR US this is the figure at or beyond which we’ve answered items 1-5. In the OP’s situation, he answered these items with a pretty clear determination that he was okay with this discretionary budget figure at 25k - all 5 questions were answered to his satisfaction.
The implicit question was "Will I find a similar compelling rational to move to an even higher expenditure if I had the opportunity to hear something even better than I’ve heard thus far?" Seems to me that this answer is different for different people; there are only factors to be weighed not proscriptions.