Best I can tell, what you are seeing is the result of a decaying good with limited use. Players who have finished the chapter have no reason to keep producing it beyond helping their fellowship, and you'll be seeing those as trades with zero stars at 1-4 ratios since they wont need anymore themselves. No help to you from those I'm afraid. The trades you are seeing at 1-1 are from the players still working through the chapter which leads to another problem. Tier 4 goods require seeds, and compete for them with Elemental Artifacts, Mana buildings, and completed techs. Now, because newer player are working through the chapters one to the next they aren't really sitting around at the endgame dumping their KP into wonders for months on end, they are unlocking new tech as quickly as they can manage. But higher level wonders increase the amount of seeds you gain which means new players simply wont have as many seeds as older ones. SInce seeds are also a decaying good most players (who don't have many to begin with) wont want to waste them. Unlocking a tech is permanent and requires nothing else, a good investment for seeds. Artifacts also do not decay which means and of them that are gained stay forever, another good use for seeds! Now ill be honest I really didn't need any new mana buildings for this chapter after having the Maze and Abbey, as well as several Frozen Fountains from the winter event set. But many players will need to improve their mana production and that too is a good investment for seeds. Then you have Tier 4, A decaying good that needs decaying goods to create, and useful only for moving through the chapter.
This leads to the unfortunate situation where goods are frequently imbalanced in the trader, and during my own progress I have seen it shift wildly between all three different goods! And the reason for this is simple: Every other use of seeds is a better investment than Tier 4! Anyone who needs it will produce it as fast as they can until the have enough, trade it as effectively as they can manage, (a good fellowship works wonders here) and then once they fulfilled their immediate needs they stop entirely until more is required. You likely have a lot of time ahead of you with your T4 manufactories sitting idle while you use your seeds for other things with lasting benefits.