Most things are different from each other. Why does that difference matter in this case? It looks a lot like traders trading in a market. That isn't manipulation.
That isn't so; I looked up an RTX 4090 on Ebay [0]. The only information I see related to depreciation is "Used: An item that has been used previously" and a representation from the seller that they weren't using it for crypto, suggesting that the seller (and the buyer; this looks like a standard graphics card listing to me) are treating used graphics cards as fungible.
