thin, very flexible, warm sounding interconnect...

You should check out DNM solid core cables. Fellow Agon member Guych loaned me a pair of their balanced cables. They sound like just what you're looking for. Very flexible, wonderful sound, seem sturdy to me. Not as sturdy feeling as my MIT EXP Prolines, but I may prefer their sound.

Goertz Micro Purl or TQ 2
Morrow MA2

Pure Note Alluvion. Flexible, strong, carbon fiber shield about 1/4" in diameter, excellent connectors. Very musical, neutral, and no edge. In your price range.

I second the Audience Au 24. Certainly thin, flexible but strudy feeling,very well made. I don't think they are really warm though, albeit very fluid and musical not sterile, cold or analytical.
If you value warmth than nothing has beaten the Cardas Gold refs for me. However you are back at wrestling with garden hoses with Cardas.

Hi all. And thanks! This is very helpful and most appreciated. I had thought about the Cardas Golden Cross or Golden Reference, but I am really trying to simplify and avoid the garden hose thing. I had to relocate my system and space is very tight. I just sold a bunch of very nice cables that were too thick to use in this new location.

The votes for Audience Au24 are very helpful. Two questions there -- is the "e" version worth the extra $$, also, it looks like on the RCA version of the Audience cable that while the cable is flexible the strain relief on the connectors extends pretty far, so if you don't have much clearance behind the components, you may have an issue? Doesn't seem to be as much of an issue on the XLR versions. Can someone please confirm?