A Low Cost Pleasant Sounding Used CD Player?

Another vote for the Cambridge Audio CXC transport.  I bought an new Open Box unit about a year ago, best $400 I've spent on audio in years.  Like you, I don't play CD's often, but when I do I want good sound.  The CXC checked all the boxes.  Happy shopping.

What DAC are you using?

Might be better to go with a CD player VS a transport depending on what it is.

Also, what is the budget?

DeKay

I'd second the Audiolab 6000cdt. Great transport for little money on used or new market.

Luxman D-N150 

you should be able to snag one for under $1500 used. 
I’ve owned my which I bought used for about 3 years now 

Also it rivals a Luxman PD -150 table with Lyra Kleos SL 

analog front end. All made in Japan so should be pretty reliable 

You know, saying low cost really doesn’t mean anything. You should state your specific budget.  That said, given what you’re looking for I’d look right to Marantz.  Personally I wouldn’t wanna buy a used CD player because you have no idea how many hours the laser/transport have on them.  I’d buy from here…

https://www.accessories4less.com/make-a-store/category/cdplayer/home-audio/audio-components/cd-sacd-players/1.html

Best of luck.