Is this another CITES issue? Ivory must be pre ban to be allowed and then you must always prove it is pre ban forever. So ivory beads are now in short supply because no sane person want to fight such a hopeless uphill battle for just a few dollars profit.
You could always recycle an old ivory bead from another gun. There have to be thousands of them out there, many on worn out guns or in gunsmiths old drawers just sitting there waiting to be found and reused. You get your classic ivory bead complete with proper aging. Or find a bit of scrap ivory and make your own. Before EBay got so PC I use to buy ivory scraps and small pieces of ivory all the time. None sold there anymore and listing some would get you banned faster than light speed. So nice to live in a modern PC world sometimes.