I use knit pick’s yarn for many my felting knits and crochets and think it is one of the best yarns at a GREAT price.  They are having a sale on their felting yarns and I am buying several balls looking to fall and winter knitting and felting.  Their Wool of the Andes Worsted Yarn is as little as $1.99 – $2.19 / ball!  Ball Content: 100% Peruvian Highland Wool
Weight: Worsted Weight
Gauge: 4.5 – 5 sts = 1
Amount: 110 yards/50 gram ball
Care: Hand Wash/Dry Flat

Check out all of their wonderful $1.99 patterns.

Also their free pattern downloads.