Lots of price fixers

Wonder if there could be a solution to combat players buying up dozens of uniques to reprice them at much higher prices.

Maybe a scaling gold tax for how many duplicates of the same unique they buy?

Maybe a timer you have to wait for to resell a unique item you just bought?

I feel like its not good faith gameplay for 1 player to have multiple tabs full of the same unique for sell because that 1 player is price fixing the item

Unfortunately a free market with 100% good faith cannot exist as it falls on the players. They can't micromanage people pricing items imo.