A Low Cost Pleasant Sounding Used CD Player?

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. 

@tsampa 

Are you suggesting something like a SONY UBP-X800 universal player

I was thinking of the even cheaper X700 universal transport!  Not something you would want to show off to your mates, but it does a remarkably good job of getting the bits off the disk and down the HDMI cables.  The remote is extremely basic, for example you cannot use it to directly select a track by its number, and its build quality is cheap!

Do you have a DAC?

I have the Oppo BDP-103 Onkyo 7030 and the Cambridge CXC, and aside from the CXC being solely a transport there is a large and notable improvement in quality (clarity, soundstage) between the three - with the CXC a clear winner, the Oppo very close behind and the Onkyo taking a distant third. 

The CXC is a little more sensitive to disc quality and I found it lagged behind my new DAC (Pontus 15th) - which was demanding a better timed output than the CXC can manage.  Still, below $500, these are all decent options.  I now run a Jay’s Audio CDT2 (zero timing issues), an order of magnitude improvement over the CXC - huge leap - but comes at a stiff price.  Oppo is a workhorse but all are old and used now.