I think I’m seeing what your talking about. It might not have a term atm or least i don’t know what its called but if you’re explaining this correctly it sounds like forced manipulation of the market pricing.
If the example of said item has a wall ( A wall is massive amount of one item) some players will attempt to break the wall and lower in the ladder way you described to keep the price low and re establish a new lower price point of new said wall.
IE:
Zin’anthid sells for say 29.99g at being of the week there is lets say 12k items , throughout the week more sellers pile onto the 12k amount making the wall larger. In attempt to re wall at lower price, said seller can cause paranoia in the market if another seller joins onto another lower price point. In sense it breaks the previous wall to what it ends up as and lets say in my example it goes to 15.99 for the rest of the week and stays there.
Some sellers also play it’s too expensive game , so they crash the market to bottom out the price then buy slowly on the way down and eventually buy out anyone who said " ohh blank " and relisted for so much lower to save whatever they could. They cause panic and then they buy out cheap.
Gordon Gekko 101