Why: If you're going to buy a knitter some yarn as a gift, don't mess around. Get the good stuff. The cashmere from Anzula is a no-brainer for one major reason. You can buy just one skein of either the lace weight or the fingering weight and your knitter will be able to make something gorgeous with it. Cashmere is expensive, but for only $35 Anzula's Squishy and Cloud yarns pack a lot of knitting into one skein. You could buy 6 skeins of cheap yarn for the same amount of money and it wouldn't feel as special as one skein of cashmere.
How much: $32 for one skein, which can easily make one project.