My binders are all custom made. They started at $350.00. Where I worked before I retired, we set up a symmetric feed binding on a Pfaff 1295 post walking foot machine . it was made for us by Atlanta Attachment
They make the best binders bar none. However, you pay for it. That set ending up costing $1350.00. Not cheap. The throat plate, feed dog, binder holder, all custom made. And that did not include the 2" clean finish top and bottom binder with a 3/8" fold over which cost another $400.00!!! Trust me, $111.00 is cheap!!! you get what you pay for.
glenn