It's very much up for debate. Your local quilt shop should carry fabric of the highest quality. Chain stores have a mid level or even carry some poor quality fabrics. What you can afford or use is up to you. I have seen some higher end fabrics at Walmart, but they are about $8/yard instead of the normal $4 and $5 and $6/yard stuff that is normal.
Avoid really cheapy stuff--coarse, poor quality fabric isn't good--no matter where you find it.
That said, I've made plenty of things from Walmart Springs Industries/Concord VIP fabrics fabric and it is fine. It is holding up well over many, many years.