In the 70's when stereo became audiophile. I saw the first over the top audio system. For speakers it used 4 Quad electrostatics, 2Decca ribbon tweeters and 2 24" Hartley subs. They were tri amped, electronically crossover with Mark Levenson preamp and amps. A Sequerra turner and I don't remember the turn table, arm or Moving coil cartridge. Total over $35,000 in the mid 70's. That would be about $175,000 in today's money. It was the first time I was told I needed to financially qualify to get to listen to the system but it wasn't the last time it happened. Up til now that 24" speaker was the largest cone speaker I had ever seen. I once saw 4-18 inch speakers mounted in a wall, no cabinets as it was using the next room as an infinite baffle.
As far as the audiophile version of the JBL speakers you kind of made my point. The raw drivers professional SRX725 for a pair is about $5,400 but the finished speakers only cost $4,000 for the pair. If you applied the same pricing to the audiophile speakers raw drivers cost $7,000 The pair of finished speakers should sell for about $5,500 not $30,000. I know this does not sound logical but if you applied the same logic to say an automobile where buying the whole car is much cheaper than buying all or the parts and assembling it yourself it makes sense. Below is my speaker at $2,000 each and the audiophile at $15,000 each I think it makes for interesting reading. The SRX725 has been replaced with a new model the SRX825.