Which Naim CDP

I've been looking for a used Naim CDX recently with no luck. NANA has a "B-stock" item in the upper $2K range which comes with 1 yr warranty. As I've scanned a'gon, a used CDX2 will go for about $3100 and a used CDS a few hundred additional. I am seeking opions regarding the value of waiting to amass the extra funds to move up the Naim quality line vs. getting the CDX now. Is the difference worth the wait? The rest of my system is Naim and I love their products. Thanks in advance for your thoughts.
David