Cone Sock Yarn Sources

From eirual :

Wool2Dye4 - sells really nice cones of sock yarn that are ready to be dyed. Also, skeins of pre-dyed sock yarn.

Webs - also sells cones of sock yarn, they are not nearly as nice and squishy as Wool2Dye4’s but - they are less expensive. $15 a lb plus shipping (if you order 4 lbs it’s $12 a lb). I find that the color is more cream, the spin is a bit loose.

Bartlett Yarns - lovely cones of sport weight yarn. I find that you really want to use a bit of woolly nylon with this to give the sock a little body. Very easy to knit, I use it to make socks on my 72 needle cylinder with no problems.

Sylvia’s Threads - Best price I have found for woolly nylon.

From sarahspins:

Lion Brand - 100% wool

I should add that one of my current favorite CSM yarns is Treadsoft from Henry’s Attic. The easiest way to buy it retail is likely from Catnip Yarns (just email them - very nice company and super easy to work with). Treadsoft is a smooth 2-ply superwash with a tight twist, it’s not only easy to knit with (it’s a 2/8 yarn, unlike most of the 2-ply sock yarns that are 2/6 and IMO a little on the heavy side), but it wears very well too.

If you have any more sources, please contact me so I can add it to this list.