I'm despising the merchant mechanic at the moment. On my live server, we've got 43 pages on the trader with people trying to get rid of ingots. 342 offers of ingots. At least with sentient goods, you could use a level 30 bee or offer 3-star trades, so the lack of options here is incredibly frustrating.
Why create a chapter with an immediate use for minerals (hub-building), an immediate use for sprouts (upgrade gate), but nothing you can do with ingots (unless I'm missing something)? Or will the equity come later, and we'll see 43 pages of minerals and 43 pages of sprouts later?
All four Element Hubs require ingots and none of the other two goods, so to build multiples of each hub, you will needs tons of ingots.