What makes an expensive speaker expensive

Simply put, I think the most expensive speakers are too much overpriced.
I understand all the money that goes into RD and all the expensive materials and expensive manpower, but I also strongly believe that there is a limit for the production of any speaker that is much much lower than its price when it hits the market.
What's the rational explanation for a speaker to cost more than $300,000? 
I recently had the opportunity to listen to one of the most expensive speakers in the world, the Marten Coltrane Supreme 2. I surely was impressed by the sound, but in the same day I listened to far cheaper speakers that impressed me as much or even more - like Canton, Tannoy, Aurum Cantus and some others. Comparing the price tags, listening to the Martens should have been an orgasmic experience! And it wasn't.
These Marten are costing the same as a Lamborghini or a Ferrari! Why? 
Too much overpriced I say...

I have been an audiophile for 50 years and have purchased a lot of very good equipment in those years.  Motivated by awareness of Floyd Toole's work at JBL/Harman, I just purchased a JBL M2 Master Reference Monitor/Crown I-Tech 5000 system consisting  1250 watts of power to each tweeter and 1250 watts to each woofer by means of active DSP crossover incorporated into the amps.  I found the system on discount at the local JBL pro dealer for $11,500 so I bought it on a lark.  
I have recently auditioned top of the line speakers from  Vandersteen, PSB, Revel, and B&W diamond 3, driven by Mark Levinson, Audio Research, Classe, and the new Vandersteen amp.  All are excellent products but my new system sounds just as good for a fraction of the cost.  I am particularly smug in knowing that it probably sounds just as good at the ridiculously overpriced top of the line speakers from Wilson. ( which, to be fair, I have not heard)  I would single out  Wilson as being particularly pretentious.  A local high end dealer who considered carrying Wilson and was wined and dined by them in Utah verifies this impression.

The same reason people buy Rolex or Philippe Patek ... status. They don't tell time any better. And after a certain price point - say, Revel Salon 2 territory - if listened to in a blind test, I doubt price (or certainly looks) would have anything to do with preferences.

Obviously too much audio gear is absurdly priced, but as long as there are buyers the vendor can keep up the sales... 

In July of 2015 I drove from Northern Virginia to Sanford Florida in order to audition a pair of used Avalon Acoustics speakers. They sounded great, I forked over less than 1/4 of the new price, we packed them into my car and I made the long drive back home. Over the next month I listened to these speakers and came to understand why they are worth the new price (roughly $45k new, used 8-10k).

Amazing speakers. Completely changed my understanding of audio and all the music I had previously listened to on other speakers. Worth the price. Absolutely worth the price, but I would not buy them new unless I would not miss the $ spent. These speakers are worth the price differential compared to lesser speakers.

In August I was in Boulder Colorado where the factory is. I called and managed to secure a tour. What I saw there were quality craftsmen building massive and complex cabinets that weigh 150 lbs each. I saw top end drivers and crossovers, and internal wiring that goes beyond what the typical speaker includes. Each speaker represents a massive investment of time by craftsmen and engineers, as well as the R&D.

What makes an expensive speaker expensive?
A target audience of very wealthy people who think more money buys the best.  Up to a point its true.  But, today's technology and understanding will hit a wall of not knowing what's the next improvement will be. After a point of some sonic benefits, its a matter of raising in price by over engineering - more and bigger... using the most expensive components that will many times become common place in the next generation..  Just look at past first generation most expensive components ... Now many are obsolete and may not even sound as good as what we now find in mid fi. ;)  And, the fact that the very wealthy will never invite you over to hear his system.  So?  He can cloak himself in a mystique that exclusivity offers him.  You will wonder what it is you are missing, when you may be missing what you already have. One of the most satisfying systems I ever heard was achieved by good quality components and a great room. Not expensive at all compared to the super systems.