Ollie's will periodically get good quality sheet sets for the price of many single sheets from Wally World. I get the set, use the flat one then take the elastic out of the fitted one. The fitted can be used for a single size or pieced with another for a larger backing. Pillow slips in the set? Either donate them or add a band of your quilt fabrics to coordinate with the quilt. I sometimes work with a group making charity quilts. Those always make my projects economical.