The price of your knitting yarn depends on its weight, fiber content, and the place where you buy it. In the US, the yarn’s weight is one of the determinants of its price. The heavier and more sturdy the material is, the more expensive your thread will be. Basic cotton or acrylic yarns cost around $5 per skein. In comparison, wool costs around $8 to $15 per skein. Cashmere, silk, and alpaca yarns tend to run on the more expensive side, costing around $35 per skein.