Doing nothing wrong. You have listened to the quilt police who tries to tell you the "right" way to do stuff. There are many ways to skin a cat. Do what pleases you. Buy an iron you can afford to replace in 18 mos. I sew on old Singers, I have an old Bernina and I feed them the thread I have available....they are so far not picky. I try to enjoy the craft not stress and spend to make someone else happy. Make yourself happy, with recycled fabric, Walmart fabric, online fabric or the most expensive stuff you can get your hands on at the LQS. If you are making quilts worthy of the quilt show the "right" stuff might be mandatory, otherwise, nah....Coats and Clark worked for our grandmothers.