The first thing I would suggest is to go to your LQS and feel the fabric they have & then Joann's and feel the $3.99/ 4.99 and compare them. You will understand then what the difference is. You can buy better quality fabric at Joann's but it is the same price as the quilt shops.
If you want to buy good quality fabric then shop at the quilt shop where you can go to classes and and get help picking fabrics etc. Where did you buy your machine ? If it was a LQS you can get classes for quilting and machine help as well. Everything you need in one place....