I'm not ashamed to admit --I buy fabric where ever I find it. Have found some wonderful fabric on WW sale tables. Once bought a whole bolt of Hoffman fabric for $1 a yard. I know the color wasn't the greatest and the pattern really wasn't either, BUT it sure worked for backings. Another time there was 60" wide fabric --bought 1/2 yard and brought home and laundered. It was gorgeous, went back and bought the whole bolt. again $1 a yard. Have found fabric at garage sales, thrift shops etc, etc. I over dye a lot of the older fabrics. Makes a whole new fabric out of them.
Buy at the LQS too, but nothing wrong with finding a bargain somewhere.