When I need to buy fabric the first thing I look for is the wide backing selections. I find that it can be so much cheaper than buying enough of the regular width. I have used the wide fabric for my piecing, for sashing, for binding, and wait for it, also backing sometimes on the same quilt, and sometimes spreading that wide piece though several quilts.
I have been using a lot of white lately, and actually just recently bought a few yards of 120" backing in snow white. I'll be using it in multiple quilts. When good fabric is at times over 10.00 a yard for a 44" piece, I will definitely pay 12 or 14.00 a yard for a wide piece. $14 for one yard of wide fabric is a lot better than $20 or $30 for for 2 or 3 yards of 44" fabric.