Making a standing thread cutter

I recently saw an item for sale much like the one above. It is used for cutting chains of quilt blocks apart. It was made of plastic, in a cone shape, and contained what looked like a seam ripper on the top. I have been using my own gizmo for a long time, years, and it was free. 

Mine is made from an empty thread spool used as the base. Then the cap of a seam ripper is inserted in the hole of the spool. Finally, the seam ripper is inserted into the cap, sharp side up when I am cutting and sharp side down when not in use. Tada! My own standing thread cutter and it was free. It also doubles as a cone holder. I have a few large cones that would wobble if I didn't use the above on the vertical spool holder of my sewing machine. 

The cap is hot glued into the spool to help it stay in place. If the seam ripper gets dull, I can exchange it with a different one. Five of mine (many were wonderful gifts) fit the lid.

I tried finding the original item again, but can't remember where I saw it. I may have remembered the cost incorrectly, around $14. In the course of searching, I found a three dimensional triangle shaped one, around $5, and a small metal item costing over $16. So in my mind, I have saved between $5 and $16 that can go toward fabric.