OK so here my ignorance of fabrics really shines. I was planning on buying a satin pillowcase for about $8 but then I saw "costume satin" fabric for $2.24 a yard and "charmuese" fabric for $4.49 a yard at Walmart, now both of these fabrics were 100% polyester is there any difference between these fabrics and the "satin" pillowcase I would buy from Sally's? Because for the price of one pillowcase I can purchase enough fabric to make at least two pillowcase......Anyone know anything about fabric? Thanks!