A lot of it depends on what size needles you're going to use, too. I think you use less yarn with larger size needles, like a 13. If you're using an acrylic for this, I suggest you buy the large one pound skeins with no dye lot. Caron One Pound yarn would be good for this. I buy mine at Joann's Fabrics. There are several places online where you can buy this also. Walmart offers it online but not in their stores. However, they have limited colors.
The prints here are only 10 oz skeins, but they're specially designed to compliment any One Pound solid color.