Best DAC for around $2,500 or less

+1 georgehifi
& kennyc

The Denafrips Terminator is a well performing DAC, if one can be obtained within your budget, it's not likely to disappoint.

Every decent piece of audio equipment that you listen to that impresses you, has been painstakingly designed by electronic engineers/audiophiles that use EE laws, measurements, specs and use test bench gear to design those pieces.

I've read so many members stating that measurements don't matter, I can't account for your experiences where something measures really bad and sounds exceptional to you...

My experience is that equipment that can read measurement extremely well (the microphone), aught to confirm that which your ears are telling you are highly resolving.
Measurement will back you up, if it's a device that performs with excellence. And if you think it sounds excellent and measures poorly, it just may mean you're accustomed to a certain "flavor", it may not accurately portray the recorded material.

I have worked at a serious boutique loudspeaker manufacturer's factory, and measurement and listening is used throughout the process. Research and painstaking matching of specifications and research into technology that performs aught to be habit, excellence isn't accidental, certainly if it's repeatable. Just as georgehifi states.

Throwing iFi Pro iDSD into the ring.  Excellent sounding DAC and incredibly versatile.

I have many dacs some very $$ .i sold a Lampizator amber3
after auditioning this in my home this has a who who of hot rodded 
brand name parts , and World class classic Analog devises 1865K
laser trimmed multi Bit dac ,or R2R great natural sonics these Sabre bit dac can’t duplicate ,power supplies make a big difference in dacs this has 9 of the worlds best Bellison super regulators ,the latest Xmos board, Vishay naked,and Caddock resistors Femto clock, and no ic chips ,Descreet op amps
with upgrade for a  bit more the Staccato Descreet opamps running in pure class A drop me an email .this bettered my friends Schiit Yaggdrasil and other dacs of much more money,nine have 
all this superior build quality and 247,000uf of capacitance nothing 
even remotely close in this price range .and 45 day return,5 yr warranty and made in USA.
https://www.mojo-audio.com/mystique-v2x-dac/

OP update, I ended up finding an upgrade Audio Mirror Tubadour III for a good deal and hooked that up last week.  The difference between it and just running the Node 2i was substantial.  The music is less "bright" and not as fatiguing and the realism improved dramatically.  A very good investment and a good first step for $1,000.  As I upgrade I'll look towards the Terminator but was happy to hear such a dramatic improvement in the music quality with the addition of a separate DAC. 

Best,
Mike