Best DAC under $ 2,500 on used market

I have been looking at Esoteric cd players.....X series, DV-50 etc... I have a McIntosh 751 cd transport with the Esoteric die cast clamp and an rca output. What outboard dac's could put me in the performance range of an X-03 or so?
I am biased towards baas extension, bass power and dynamics.
Thanks for your advice.
I also have an MCD751. I run it into an Esoteric D70 DAC. You might be able to find one in your price range.
I think you have many choices in that price range.

If it were me, I think a newer model Bel Canto DAC would be high on my list.

IF your system uses SS amplification, I would also consider a tubed DAC. You could start with an mhdt Havana (<$1000) and maybe move up from there if you feel a need.
You might want to check with Steve Nugent at Empirical Audio as a safe bet. For that kind of scratch you could get something new from him plus he is always up on the latest in technology. He has a new DAC product that you might want to talk to him about.
Musical Fidelity TriVista 21. It has exotic tubes and is built like a tank. Sounds very good, I have seen them for $1100. A steal. Several companies rebuild them for even greater performance, something I may do someday. Especially good at driving passive preamps.
The Bel Canto and Bryston new DACs are in that range and are pretty darn good. They represent the latest in technology - DACs loose value as new formulas come out, I'm not sure you'll do better with used over those two at around 2 or 2.5k. With amps or other stuff, I wouldn't say that.
Apogee Rosetta 200 or Apogee mini dac at half price if you dont need AD conversion. With fireware card also opens the door for the (present) future. Dac made for pro studio purposes. As it was made for the pro market, one could be sure that price is in line with sound quality. Very detailed dynamic sound reportedly with somewhat warmer presentation than the Benchmark. Accepts signals up to 24/192.
What do people think of my favorites from the past: Theta Generation 5 or Basic 3, and Monarchy Audio? Also Encore, rare but great.

You might want to consider starting your own thread or posting on a more recent thread than one from 2008.
Why not go new and check out the NAD M51? It's only $2000.
Agree with last_lemming. NAD51 is a killer unit.
There was an mhdt Constantine DAC listed on agon the other day if still available for under $300. I would recommend trying that first before spending any more. I did a few years back and it is still running as my main source in my main system that I spend hours a week listening to.
You can find a new PS Audio PWD MkII in this price range, and used for sure. This will do it all for you; terrific DAC.

I 2nd a PS Audio PWD MkII with bridge and don't forget to replace the fuses with HiFi Tuning Supremes. Like computers, it's remarkable how much you get for little $$.
Haven't heard an Esoteric X-03, but I had a Bel Canto DAC3VB in my system for a while and it was to say the least excellent (if I could've afforded it, it would still be here). It's very good on its own, but with the VBS power supply it goes to another level entirely. Transparency, micro/macro dynamics, 3D soundstaging, tonal nuance, and a quiet backdrop are among its strengths. If you can find one used it might be in your price range, and it's hard to think you'd be disappointed. Best of luck.

Just noticed this post was from 2008. Ugh.
If you are looking for used, try the Luxman DA-06