Why is Strong Health Potion so cheap on the market?
Dear Tibian Sages!
This questions is related to my more general inquiry into the state of the market, but probably has a straightforward answer.
Why are Strong and Great Health Potions so cheap on the market? On Refugia, they go for 10 and 35 gp/ea respectively [SHP: 115 gp @ NPC]. Similar NPC-sourced items are within a small range of the NPC-price: for instance, Strong Mana Potions have market value of ~112 gp/ea [liquidifier prices; 93 @ NPC].

So, the questions is: what is the source of cheap health potions that made the prices deteriorate by greatly over-supplying the market?