I have been collecting fat quarters for a quilt I am planning that is appliqué and requires many colors. At first I just picked up some FQ in any color, but now that I have a lot I am filling in the missing colors (blue) so I have a variety. Paper piecing does take more fabric, but not a lot, and FQ go farther than you think. If you plan to vary the colors from block to block--pink or green for example you will do fine with FQ. They are a great way to get a variety for not a lot of money. Good luck with your quilt and your hunt for fabrics.
Sue