Check out half price days on scrubs! They are usually made of good quality cotton and the tops often come in cute prints. The larger the size you can get the better! For solid colors, get the pants!
I've made lots of I Spy and other kids quilts using scrubs.
Also, bedskirts. Be sure to check the fabric content as many are poly, but you can find some like new in pretty cotton fabrics.. Bonus, the thin fabric of the bedskirt top can be used for foundation fabric in string quiltings.