Is a dac better than an new cd palyer?

First of all , nice place to post the question... :-)
You will get better response if you put it in Digital.
It would be actually helpful if you specify your budget.
Generally speaking, stay away from changers…

SACD players can accept an external DAC for standard CD playback (all that I am aware of anyway), so the DAC will not become obsolete in this sense. Just be certain that this holds true of the model you select. If your changer has a coaxial/digital out and/or a Tos Link out then it can be used with many DACs. The trick is finding one that you like the sound of. I did not find some of the "new" DAC's (as of a year ago) to be an improvement over the stock DAC in a CAL player, so care is needed when selecting a unit.

Unlike Dekay, I am very happy with the Classe' dac I used to upgrade my CAL CL-10 changer. So far, I believe that it gave me a major upgrade in sound while preserving the party friendly changer.

I went to a used Muse 296 with my Arcam CD player. It made a huge difference and I love it.

Swampwalker: Never tried the Classe, but did end up with the Bel Canto 1.0 (and later the 1.1) DAC for over a year, which I enjoyed. I just found some of the popular DAC's to be too bright, thus not better, IMO.

If you can find a good DAC used I think it would be the way to go. I got a Pass D1 and with any CD as a transport (even my old Sony ES) it sounds better than any of the new CD players I auditioned.

Dekay- I've gone thru a major upgrade over the last month or so, so its hard to isolate specifics. The DAC came first, then new speakers AND cables, then a step up in power to drive the new speakers. But I did really like the sound when just the DAC was added. Of course, its not an inexpensive dac, but this way I can keep the changer that my wife likes AND improve my source. I don't believe that there is a better changer than the CL-10, so that was my only option. I'm running the DAC balanced into my pre also, with better cables, so I'm sure these are all adding a piece to the puzzle. Luckily, these selections have all worked out for me, and with business being good, I was able to stretch my budget a little (OK, a lot).