Point of diminishing return for a DAC

I am currently using a Mac mini as a Roon Server with an entry schiit DAC. I am considering buying another DAC. My question: what are the opinions on the point of diminishing returns for a DAC. My system is Golden Ear Triton 2+, Prima Luna preamp Carver tube amp. Quobuz for streaming...

Look forward to thoughts and advice...
Here is my two cents worth.  I had several ~$1K DAC and they were all indistinguishable from one another:  Jolida, Channel Islands Audio, Denafrips Ares, Schitt Gungnir,  and couple more that I have forgotten.  I upgraded to a used Ayre QB-9 and was absolutely astonished with the SQ improvement immediately!  I then upgraded to an Ayre Codex, with a similar sound, which allows me to stream my Oppo through the DAC.  It is fantastic for a very reasonable price.

I visited a friend of mine in Italy his summer who used an upgraded Denafrips Terminator and I was absolutely blown away with the sound of his system with his Buchardt S400 SE monitors.  It is among the finest, most natural sound systems I I have ever hear, regardless of price. 

He has since upgraded to a Chord Hugo (~$10K) and is ecstatic with the improvement in SQ.  He is adding the Chord M-Scaler device to the DAC (~$4K) and expects solid SQ improvement.  I do not doubt the dual devices are in the realm of the uber-expensive DCS multi-component DAC system.  

I know that there are some sub-$2K DACs around that get rave reviews, Holo is one of them and Audio Mirror is another.  Worth a listen, for sure. 

My take is that more or less you need to spend ~$2K to play in the big leagues of DAC's.  The Ayre Codex and Schitt Yggy will get your most of the way there.  
I went from a bifrost to a chord hugo. Law of diminishing returns didn't apply there. HUGE difference. -Elevik
+1 - I upgraded to Chord M Scaler and Chord Hugo TT 2 this summer and quite happy.  
I bought a nad m51 and liked it so much i bought another to use in my other system. 
Fastninja , Doug Schroeder comment pretty much nailed one of the mistakes made when wanting more quality out of playback.
i know this to be true having experienced this myself a few years ago when an audio acquaintance with good intentions installed his IMac Pro in my system comparing it directly to a transport I wanted to transition away from .
It was different however I immediately knew the sound quality didn’t equal playback from transport, sure the convenience was fabulous using the Mac though I wasn’t looking for convenience alone.

later that year another audio friend let me listen to a smoken good server in my system that immediately convinced me 30 seconds into a ripped favourite this was the path to better sound playback for me anyway.