If its being used for foundation , I would not be fussy . But Do preshrink, the lower quality will shrink alot more than the more pricey.
Really any fabric can be used for a foundation( as long as its washable) . Its a good way to use up some of those "what was I thinking" fabrics.
Some use regular copy paper , using a small stitch like you are paper piecing. Then remove the paper once its sewn into the block shape. I know some thrifty people who use newspaper ... I am not a fan as my newspaper the print rubs off too easliy .