Which scenario are you referring to? The one where everything is cheap because of ai or because the acidic oceans?
Various sea organisms rely on calcium carbonate for the formation of their shells and bones. If the water is too acidic there less calcium carbonate in the water…
Oh and what Im getting at is that things like food don’t necessarily have to be cheap because “ai” produces goods. Ecological collapse can make essentials expensive regardless of who produces the goods.