The local Walmart in the town where I work has always carried fabrics but they have recently added a section of quilting fabrics. From what I have checked out it seems to be quality fabric. Now, the fat quarters are a different story. Very flimsy material.
I am lucky in the fact that our local grocery store has a Ben Franklin area inside. I call it my "personal quilt shop". They have more fabric than I can ever see at one time and carry many of the quilt shop brand names. Their prices are fantastic. Best part...they usually have a fabric sale once a month with fabric, books, and patterns at 30% off..no coupon needed. Plus they have a fabric club where you earn one free yard for every 50 yards of material you buy.
I am with the rest of you, as long as it is good fabric, it doesn't matter where it comes from!