Honestly, as long as people can still make a profit from crafting, the supply costs are reasonable. If people don't like the costs, then they'll just gather mats themselves until the prices tank because nobody wants to buy anything.

I was able to move aethersands at a decent clip for 5K each when SB first dropped, but the bots swiftly crashed it all the way down to 1.5K within a few weeks of them becoming active.