Upgrade from BluNode 2i with a new DAC or Integrated Streamer DAC?

Thanks.  Your reply seems practical , useful and seems consistent with some other chains with the price limits I have set.  Many of the chains when getting lengthy seem to digress into confusing arrays of nuances as the $$$$ for components goes up.  Given I have 77 year old ears I'm not sure how much more upgrading I will be able to appreciate but I am finding listening fatigue with the Blue Node 2i compared to my vinyl listening.  My old Mark Levinson 26 has it's own seperate power supply.  I understand why that makes a big difference with a pre-amp.  I'm not clear how that would improve either streamers or DACs.  Perhaps it is relative such that the potential for a negative impact of fluctuations from the wall are greater for a pre-amp that the other components.  Would a pre-amp be more sensitive than a DAC and a DAC more sensitive the a streamer?  I ask this noting that some better quality streamer/DAC/pre-amp units like high quality pre-amps include or offer a linear power supply while I don't see the linear power supply being pushed with mid-(under $10K) DACs and mid-priced streamers.  I'm just thinking down the line that a $300 - $500 linear power supply might make the budget, especially if I could conveniently trial it.  If so would you put the LPS into the streamer or the DAC?

Thanks again.

Any opinion on the Matrix Audio X Sabre PRO?  How would might it compare to the Denefrips Pontus II.

I would one last question.  New vs used bang of the buck?

Sois:  Thanks for that article.  The head to head was helpful.  Ahh, the subtleties of taste highlight how even the engineering of electronics at some point is an art.  The rate of development in that art is more than a bit mind boggling.  While I keep waiting for what’s next, I keep eyeing both the limitations of my bank account as well as the clock on what’s left of my own listening experience which is pushing me to decide.  

Thanks all.  Went for the Pontus II 12th new after all.  The used Matrix Audio X Sabre PRO I was looking at had been through two owners making me wonder if it was somehow less satisfying.  Some other genrally favorable reviews implied that a bit as well.  My Maggies have always highlighted the detail at the expense of dynamics to a degree so I am hoping this will bring out the strength in detail of the old maggies.  No opportunity here to audition in home with my own system.  Also newer technical advancements seem to still be coming along at a brisk pace.  Warranties and a reputable dealership seemed worth the couple of hundred $$ saved going to ebay.  Decent quality shielded power cord, balanced XLRs and and digital RCA connector exhausted the budget for now.  Maybe the Iris or something to clean up power from the wall later.  I am anxious to hear how this one piece changes things.  I really appreciate the input.  Give me some time to break in the DAC and I'll post again in month.