Sleeper CD player DAC

Would like to know what CD player  or DAC units offer incredible sound for low cost on the used markets 

i.e. Cary 306/200

can u recommend another player that sounds like this unit? 
The cary 306 retailed for $8,000 when new. At nearly 10 years old, I would expect its value to be half that or even less. Still not "low cost" in my book, but hey, its a good problem to have. 

For that $3-4k (and less on the used market) try to audition the Yamaha CD-S2100. Much more recent design, flexible (cd, sacd, USB dac), and the build quality is fantastic.  A "sleeper" in the sense that most expect 90's mid-fi black boxes from Yamaha, and not something of this build and sound quality. 
PS Audio DirectStream DAC.  Current and latest technology, free firmware upgrades.

one on eBay at about half retail (not mine).

@yakbob, @dvdgreco,

"For that $3-4k (and less on the used market) try to audition the Yamaha CD-S2100."

 " the build quality is fantastic." 

Can't agree more about these Yamaha players.

I have the baby brother Yamaha A-S1000 and it too is built like a brick at 33lbs.  If the 2100 is a bit too much $$$, the the CD-S1000 or CD-S2000 might be another option.  Neither has the outboard DAC feature but none the less they are incredible players that can be found for as little as $600.00(CD-S1000) on the used market up to $2000.00(CD-S2000) for new.  Refurbished fall somewhere between the low and high.

Also, a Cambridge Audio 840C or 851C, which do have DAC feature, might be a good choices.

" can u recommend another player that sounds like this unit? "

My Wadia 861SE is a better sounding unit than the Cary. If that's too much, I have a Wadia 302 that's very good as well. It's about the same as the Cary.

Ayre CX-7 and the 5 series U2, are also good choices. Resolution Audio Opus as well.
+ 1 for the Yamaha's .  Their new intergrated amps are great as well.
CD player - Esoteric DV50S 
New, it sold for $6,000. You can now pick one up used for ~$1,000.

Even cheaper is the Sony S9000ES that you usually find for under $300.

As for DACs, the Teac UD-501 can be found used for ~$500. In the higher end, you can find the Lampizator Amber for ~$2,000 or the Bricasti M1-SE for ~$5,000 (50% off new). 
Lampizator Atlantic Plus is a killer for the money!
For $750 a used Rega DAC-R still under warranty can be found - just ask.