I worked for Jo-anns and know for a fact they buy mostly 2nds in the fabric. End of bolts/runs. They buy the same fabs that Walmart does.
I do think that some of the newer quilting fabs are of better quality.
look for the ID of manf. by the printing on the side of the fab... I am not a fabric snob... but try to use only 100% cottons no matter where I buy them..I work to hard on my quilts to use a cheap fabric.