Need advice on rich sounding cables

Agree with both Mitch2 and Chayro. IMHO, a cheap but well matched cable is better than expensive ones plus you can use the extra money on something else for better improvements.

I have the YG Anat III Studio Signature.
I'm also very familiar with Kubala Sosna as I've had the Emotions for about 4 years and I currently use the Elations.
They are both very well balanced from top to bottom, however the Emotions do emphasize the midrange/mid-bass a bit more than the Elations do, which happen to be totally neutral across the entire frequency range.

I was originally using the Emotions with a pair of Kharma Mini Exquisites which had a ceramic midrange and a diamond tweeter, so this cable was a great match for my tastes since it perfectly subdued the upward tilt of that speaker.

When I bought the Anat's 14 months ago, I kept the Emotions on them due to lack of funds, but I felt like the Emotions were holding back the Anat's in the areas of speed and transparency. So, about 9 months ago I upgraded the Emotions to the Elations via Kubala's upgrade policy. I am very thrilled with this upgrade as I feel the Elations are providing everything that I was looking for.

Description of the differences that you are asking about:
Neutrality: rated 1-10 with 5 being perfectly neutral.
Emotions=6.5
Elations=5.5

Bass:
Emotions: very good deep bass, a little slower than the Elations. "fullness" greater weight, some of this may be due to the fuller mid-bass.
Elations: Excellent, fast and taut bass. "tautness" greater speed, more athletic like a basketball player.

Highs:
Emotions: silky smooth, not etched
Elations: silky smooth with increased transparency and air.

Timber: Both cables have fabulous timber.
Emotions: Excellent woody and natural sound of the double bass
Elations: Outstanding woody and natural sound of the double bass and you can add an increased robustness and realism to the sound emanating from a solid 3-D real instrument. Perfect pitch as well.

Vocals/ Midrange: the Yg's do vocals so naturally.
Emotions: sweeter, perfect recording of a vocalist.
Elations: More Transparent as in a couple of veils removed. The vocalist is in the room at times. Better instrumental and vocal shadings.

Speed:
Emotions: slightly slower, holds onto the notes a bit longer like a top tube preamp would. Increased Harmonics, richer sounding.
Elations: faster, better PRAT. more transparent. Excellent Harmonics as well due in part due to it's increased ambiance retrieval, as opposed to holding onto the notes longer as the Emotions do. The Elations also have a better transient attack; as in piano strikes, string plucks, drum strikes. Clearer window into the recording venue, whether that may be the recording studio or live soundstage.

Imaging: they both image very well and I would give the edge to the Elations for front to back soundstage depth, image height, ambiance retrieval and resolution. There is also greater instrument separation and air surrounding the instruments through the Elations. The back wall also disappears better with the Elations.

I have seen the Elations 2.5m used within your price range of $4000.
The Elations are better in every area. I would think the Emotions are better at taming a brighter system, and smoothing out any grain, stridency or hash or for adding a richer, fuller sound to a thin sound system. Keep in mind, hadn't I changed my speakers, I would have been very happy keeping the Emotions in my system permanently, as it represented a perfect match at the time.

With the Emotions the Speakers disappear as a sound source.
The Elations even go one step further, in that it seems like the speaker cables disappear and the speakers aren't even hooked up to anything.

The Elations are just purer and untouched without any additions or subtractions, just like virginal snow.

Another cable to consider is the Kaplan cable (now Waveform). I also have the YG Carmels (great speaker) and the original Kaplan GS provided a great match, besting my Audience, Highwire and JPS SC3.

They side very slightly to the rich warm and sweet side of the spectrum, with a detailed and open midrange, and without any (!) harshness in the highs, providing lush tonal colors and density. As Henry Wilkenson said in his Audiophilia review: "After inserting these cables in my system, I noticed that my listening sessions became far more frequent, more enjoyable and often extend into the wee hours of the morning. I attribute this to my systems’ new found musicality."

I liked them so much I purchased a second pair to biwire, and though that provided some improvement, especially a tightening in the bass, I'm not sure the extra scratch is worth it over single wiring with my Audience jumpers.

Another cable to consider that I'm also quite enamored with is the MG Audio. They're a bit less rich and warm though, and more extended / accentuated in the highs, and more forward and dynamic, but they do add an amazing life and sparkle to the music that really gets your toes tapping. Color me torn (I've been switching back and forth, pleased with both).

Cardas Clear

Cardas Clear will provide exactly what you are seeking!