Significant steps? (DAC)

Thought I'd get some opinions on where the significant audible steps are in DAC/DAC amp/stack are.   Sure, ESS sounds different from AKM, Op amps are different. Good discrete class A can be different. Tiny tiny differences.  Where are the big differences. Big for a Dac of course as there is little real difference from a Apple Dongle to a Pontius to insanity? 

Step one. The dongle. $12. Good for portable. Most would agree, not quite hi-fi but actually listenable on the move. 

Step Two. Real DACs made for hi-fi. $200 stack, DAC/amp. e.g Schiit or JDS stack, Topping DX3pro+, etc. These can be pretty good. Similar to respectable internals in integrated amps of respect.  Popular priced, high volume,  chip based.  They all sound about the same to me.  Maybe with $1000 headphones you can pick out differences. The better of them "do-no-wrong"  which is significant in my book. The Sabaj A20 and the Gustard A26 have the same chip set, both mass produced, op amp etc.  Why a 3X price difference? Just the streamer feature? Is this group, sub 1K maybe, where the "all DACs sound the same comes from?  Or like me, having heard an expensive but not very good one biased them into a steadfast spec chasers?  ( Bad experience, but my mind/ears are still open) 

Step three.  It gets harder. I would expect not just not bad, but something actually better.  Different moving to the cheapest R2R or higher end D/S.  Is the  difference from the DX3 to a D70 really significant? RME in here?  Better or just different to justify 2 to 5 times the price?  Every reviewer at this price claims every new one is worlds apart and the new budget champ. Really?  Higher price may be justified as more expensive chips, R2R are of course difficult, better power supplies, better output buffers. Without direct comparison, is this a level you can live with happily and just listen to the music? Are there still actual flaws in the performance? Do you need to have a system appropriately balanced components with speakers above 10K to hear the difference?  Can you hear it on an Audiolab integrated and set of Sonas Faber Illuminas? 

Step four. Expecting serious entry to high end.  Is it at the maybe Mearson or Gustard R26/A26 level? Qutest?  Or are these really small increments from less?   Is the real step having to go Holo or mid-line Denafrips?   2K or is it 3? 4? Where is that "real" step? Does dealer vs direct sale move things between steps? What would a Aris cost if it was through a dealer chain? Price difference and the need for a preamp would put it almost 4K.  Is that good?  

Higher?  After several grand, does it really cost more and justify higher prices, or are you buying the case and prestige?  I have probably not heard the right ones, as the upper end I have heard, the difference to my bottom end was very slight. Does a Birkman or Berkley really change things? What can they do in a box at DCS that is worth $140K that actually sounds better than one for 3 or 5K, or $200 for that matter? Maybe technically close to perfect, but how far above the studio recording and mastering makes any difference. GIGO. 

So, where are the dividing lines that separate significant performance differences?  What product is a bulwark for that tier?