So, basically people selling DAC's at 2k are more or less ripping you off? Especially when you have a Topping or SMLS dac that has the same numbers at a quarter of the cost?
That would depend how they're selling it. If they're telling you it sounds better then yes, they're probably ripping you off. If they'll selling it on features, bragging rights for great specs, build quality/warranty, or just general coolness factor then no.
People say the multibyte dacs that run 2K and higher are great sounding pieces of equipment, its all mental?
Yes.
This dac https://www.moon-audio.com/matrix-audio-x-sabre-pro.html , the Matrix X has no audible better difference then something like the D90 or M500? Honest question.
Nope, won't sound any different to humans under controlled conditions. It does have more features and gives you bragging rights for being tied for first in the ASR SINAD ranking though.
There is lots and lots of BS in audio but that doesn't make everything that's expensive a rip off. (Even if a lot of it it...)
Something I personally find odd about audio is that almost no one will admit to spending more money based on something being cooler that a cheaper option. In comparison to another hobby, no one has this problem with cars. People will spend thousands upon thousands on purely cosmetic upgrades. People will "stance"their cars to make them look cooler at the expense of performance. People will buy brand new sports cars based on styling and brand exclusivity instead of raw performance numbers.
And no one ever questions this. No one tries to invent new laws of physics in order to claim their Ferrari really is faster than a less expensive Corvette despite the Ferrari's slower 0-60 times. Most people accept that someone will spend a lot more money on something they think is cooler and don't care as much about the absolute limits of performance because both are already way too damn fast.
Very few people in audio can admit this though. For sellers it's almost always "this special way of doing things sounds better" rather than "check out our cool and special way of doing things". Buyers can't admit they made a decision on something other than pure sound quality so they use any argument available to justify the higher sound quality whatever they purchased must have. This seems to to create a feedback loop with marketers catering to delusions invented to reduce cognitive dissonance via buyer's remorse which just creates more cognitive dissonance and more delusions.
At least for the electronics. There's more leeway in transducers.
Anyway, there's my rant for the evening...