We see it in oil all the time
Suppose the dollar devalues by 1/2?
When does the cost to a domestic provider of oil get anywhere near the cost of importing a barrel of oil.
It doesn't.
So, why do we pay the same for domestic oil that we do for imported crude? It is because the oil companies could sell that same oil, we use domestically, on the open world market for the world price. Being a free capitalist economy, we cannot require the oil companies to sell their product domestically for less than they can get elsewhere. Therefore, we pay the world price for oil, even if it was pumped out of the ground one county over for a cost of $.25 a barrel.
So, what does that mean for food? Gee, if the food producers can sell their product overseas for twice what it sells for here, what right do we as citizens of a free society to deny them that right? Bottom line, we don't. We will end up paying the world price for all domestic commodities using money that is only worth 1/2 what other competing buyers money is worth.