They are available in multiple quantities on eBay from this seller: jaswenson1
I was a little unsure because they looked a bit different than the pellets I had been using but was pleasantly surprised!
They weigh about two times more than your standard polypellet and I LOVE the extra weight they add to the baby's limbs without making them hard they way glass beads do. I am thinking now that I may not need to use the glass beads at all since I found these
which is great because I never fail to make a mess with them!
I ordered 5lbs for $20.00 and got free shipping so the price is great too.
I have so far only had one transaction with the seller but it was a pleasant one with pretty quick shipping.