Not sure what machine you have, but the walking foot is my can't do without. I leave it on one of my machines at all time. The 1/4 inch foot is very nice, but I can put s barrier up to help keep the width. And if you plan to do the free motion quilting then the darning foot (open) is necessary.
So it really depends on what you plan to do.
You need to make sure the walking foot is one that goes to your machine. Mine cost about $25.00 in US which was for a Singer machine. The Brother appears to cost more.