Great question!
I have recently been in search for a "cost no object" (within reason for me) speaker. I have listnened to quite a few and have found that most of the time, the difference in price does not correlate with the sonic gain, except for two speakers.
The Rockport Antares and the Kharma Exquisites are the exception. I heard the Rockports in a somewhat difficult room (very low ceiling) and they were MAGNIFICENT! They absolutely disappeared and were so seamless, it was reminiscent of a planar / ribbon with none of the drawbacks associated with those types. The Exquisites did the same for me. Both are gorgeously built, neutral and incredibly dynamic. I wish I had the opportunity to hear them in the same room, but alas, that was not possible. Both were on a totally different sonic level than I have heard before.