Great thread! First as several others have said do not impulse buy fabric and build up a purposeless stash of fabric. I've quilted for 20 years and still have some of the original purchases. They are dated and I have an unmanageable collection of totes, bags and boxes which I'm frantically trying to use up so I can get the styles and colors I now love. I would now buy for a project and complete the project, not just impulse buy. I usually don't have enough of the stash yardage and can't get more. Works great for charity quilts and is certainly much cheaper, but very guilt producing for me.
Second is you do not need a machine with 100 different fancy stitches and options for quilting. A heavier duty basic machine is perfect for quilting and basic sewing. I bought a Pfaff 7570 years ago, but then added bigger, fancier Janomes because I thought I needed the size and features. Not true. My go to machine is still the Pfaff and I would be thousands of dollars richer.