If this actually happened, people in the interior wouldn't be able to afford the food they were selling.

I guess it will become a sort of inefficient, hyper-federalist system.

Seems like having the interior pay its own way by selling food and other resources would be quite a lot more efficient. It would also allow people to govern themselves how they see fit. It's a more humane solution IMO.

Why inefficient? Easing the burden of centralised government on all interstate trade should be more efficient, I would think