I have one and use it a lot. I don't have the specific cutter, but do have a tiny Olfa one which I can't find blades for. Probably why it was cheap!!

Go in your kitchen and pull out a side plate, measure across the top and find one that's about the diameter you're after. Plonk it upside down on your fabric and voila!! This way at least you get to make a circle type quilt and find out if you'll ever want to make another....