Sorry, I cannot really help you there as the CNC tool fabricators are often quite "regional".
What I can share is that one of our collaborators bought huge foam milling bits (like 40cm long) from China for quite cheap (like 1/4 of what we would have paid in Germany) and all three would start to vibrate a LOT before even reaching the RPMs recommended in the manual. Fortunately one was balanced enough so that we could use it. That made the deal not as great as it seemed.
Also, that Chinese company tried to declare the value of three huge milling bits as 20USD, which customs also did not appreciate and delayed their arrival.
So rather than looking for a reliable, international tool fabricator we personally switched back to using a local source.