One way to get some very low priced stash is to go to thrift shops (such as Goodwill) and look for good quality, 100 % cotton men's shirts and cut them up along the seams. You can get the equivalent of 1 to 2 yards of fabric from a large to an extra large shirt, depending on the cut, short sleeves or long sleeves, or the size.
You can also look for woman's large cotton shirts or dresses to use also.
Our Goodwill has items on sale half price after they have been there for a certain number of weeks, and on sale for 75% off the next week. I usually wait for shirts to go on the 75% off sale and get them for 75 cents or a dollar. Can't beat those prices.
As an extra bonus, I also keep all of the buttons that come off the shirts and build up a great button stash!