If you go to websites like Swappa right now, you can find brand new Google Pixel 9 models for less than $600. Considering Google is trying to sell these phones above $800, I think the market already decided what this series of phones should cost really.
I mean my assumption is that those phones are stolen
I don't see why anyone would list them that low otherwise, they've not been around long enough to not sell and have the seller drop the price out of necessity.