rikagaku chalk in europe

Little off topic for the chalk snobs. A coworker told me about this chalk and said that they were quite good. Wanted to see what the hype was about. Are there any shops/sellers where you can get them for a reasonable price in Europe (more specifically Benelux/adjacent areas of germany/france)? Shipping fees from east asia are incredibly high, to a point where it's simply not worth it anymore for me.