Never by 'cheap' quality fabrics. You will make cheap looking quilts. Find a couple places that has 'good'
quality fabric, but has great sales. This way you get good fabric for reasonable prices.
I buy from Ericas (Indiana) and fatquartershop (Texas). Both places have great sales with fabric 40-50% off.
This is quilt store quality fabric because these are quilt stores. Sign up for the newsletters and you will be notified when they have sales. Choose a couple quilts to make and purchase only fabric you need for these quilts.
That way you don't purchase fabric you may not use. Happy Quilting