SACD player recommendations budget 3k.

My first SACD player was a Marantz SA 8004.  I replaced it with a secondhand Denon DCD-A100 a couple of years ago, which was a noticeable step ahead in sound quality.  A few months ago I acquired a new Denon DCD-1600NE, and the DCD-A100 went into storage.  I was happy with the DCD-A100, but wanted a new, current model so it would be under warranty and I could take it to a Denon service facility about ninety minutes from here. 

I was surprised at the sonic improvement.  I'm still working my way through the collection, rediscovering everything.  SACD's sound better than ever, but the improvement is larger for redbook CD's.  The two Denon models have progressively narrowed the gap between SACD and redbook.

kren0006:  I own about 100 SACD's and 700 CD's.  I became interested in SACD's about two years ago.  Persuaded that SACD's were always better than redbook CD's, I bought many pop and jazz titles, both new and used.  And I learned the hard way that it's more important to find the best mastering, starting with checking the dynamic range.  I ended up replacing maybe 20 of the SACD's I had purchased, sometimes with regular CD's.

Other things being equal, SACD still beats redbook CD, but as I mentioned above, the gap narrows with a higher-quality player.
There is no substitute for research.  If you are considering a multichannel SACD but plan to play the stereo layer, make sure the stereo layer uses the same mastering.  If its dynamic range is much less than that of the multichannel layer, it probably is a different mastering.  There are also some notorious cases out there where the redbook layer of an SACD used the same mastering as a previous redbook CD rather than the mastering of the SACD's stereo or multichannel layers.
Be sure to check the DR of any SACD released at the height of the loudness wars, circa 2005.  There is a lot of dreck out there with DR of between 7 and 9, and the SACD format does not make it any less so.
If you avoid the pitfalls, SACD sound quality definitely rewards the effort.

I can address only one side of that question.  I overhauled and expanded my CD/SACD collection during the last eighteen months.  Most choices were researched by checking http://dr.loudness-war.info, which contains user-contributed dynamic range reports for many pop/rock titles.  I checked the dynamic range of discs I already owned using the TT-DR Offline freeware.  Dynamic range is an important data point, but not a litmus test.  Variances of 1 point can be ignored.
The most time-consuming (and absorbing) part was the Steve Hoffman Music Forums, where the main focus is mastering.  Simple searches like "best version of XXX" often bring up lengthy threads.  Sometimes they are a waste of time, but often they contain valuable information, and I have come to identify some posters as more or less in tune with my own preferences.  If, like me, you had become bored with the mediocre CD's accumulated over thirty years, you will learn why--better, you will learn what to look for to replace them.
Other places to check, if you need to, are http://www.sa-cd.net/ and Amazon user reviews.

Finally, I checked Discogs to see what versions were produced.  This is the best way to see if a title is available in SACD.  It works very well for pop and some jazz, less well for classical.  For-sale listings on Discogs are more tightly rated and described than on the well-known auction site.  Determining the version sometimes gets right down to what the tiny printing in the center of the disc says.
All in all, it's an adventure.