What makes a DAC so expensive?

I see some good points on this thread. People actually understanding manufacturing costs, engineering, etc, and seem to relaize the last extra costs exponentially more. Then I see djones as usual poo pooing anything that costs because he can’t afford it. I can’t afford a dcs stack at new cost, and also keep everything else I have. I could,  it that stack wouldn’t be much use without amps, speakers, etc etc, lol. Dosnt mean I wouldn’t like to have one if I could. 

@speedbump6 

couldn't agree w you more... cheers

As I don’t have access to Djones financial records, I personally would like to focus on his reasoning, which is sensible as presented. If a $200 DAC measures .0006 THD+N, are we looking at an output value and how does power supply and/or OP amp compression figure into this measurement?

I have no desire for a dCS stack as it wouldn't provide anything audible that I don't already have. 
Take a little Topping E30 DAC it has a SINAD of -113 and the THD +N is about .0024% which is about -95dB. 
The Linn Akurate DSM has a SINAD of -110 and a THD+N around .001% or about -100dB. 
Both of these DACs reconstruction filters roll off the high level frequency above 22Khz as required by digital audio theory. 
Perhaps some people could tell one from the other in a blind test I doubt I could.
One DAC is $139 the other $10,500 in a sighted test which one will win consistently?  
Power supply noise and OP amp compression isn't that important as long as the output measurements are extremely good as long as the DAC can cope, if it can't then you don't have a well engineered DAC. 
Which of the 2 aforementioned DACs have power supply issues and reconstruction filter problems?

One DAC is $139 the other $10,500 in a sighted test which one will win consistently?

I think i am with djones about that, not because some technicalities about measures numbers prove that improved technological advances are inaudible.... I am not sure ears are so well understood in their astonishing capacity to retrieve information from sound ....

But i sense no limitations in upgrading my sonic s.q. for the last 2 years to another level completely and my modestly price dac was never a limitation and never reveal any of his own limitations to me if there is some...(I am sure my dac has limitations for sure but whose dac has none ?)

I think really that, except if my dac was a miracle at low cost, and i think it is one anyway, perhaps also limitations  seeming to come from dacs are coming sometimes from a too much sophisticated technology in relation to the rest of the gear or rather reveal limitations in relation to the 3 embeddings of the audio system more than from the dac itself, or comes from really too digital sound harsh  bad dac....All the dacs i owned before the last one were bad, even the best one, in spite of glowing reviews.... They all were low cost one for sure....

My best purchase in Audio was this dac.....Starting Point Systems NOS dac....There exist no negative reviews of this dac and some talk about his limitations being a lack of details....I was thinking  the same the first month i listen to it, perhaps a bit lackimg in details....

But with my upgrading embeddings many controls improvement that put my system on another level totally, i realized that the seeming lack of details was coming rather from a wrongly or defective mechanical, electrical, and acoustical embeddings of my audio system, not from the dac at all...

Then what is the value of reviews by reviewers that listen to compare many dacs in a not so well embedded audio system and room?

Zero....

Because the best dac in the world, if there is one, must theoretically have no sound of his own, it is a translator, the defects are then coming from the audio system embeddings....For bad dac, all people know what is their sound: harsh,digital, cold, analytical etc....Or too warm, lacking details etc

A good dac does not exist, it is his best quality....

My dac do not exist indeed....

:)