Point taken, but you could imagine a state of affairs where the costs of trade are so high that the imbalanced prices do actually represent equilibrium, e.g. im

Point taken, but you could imagine a state of affairs where the costs of trade are so high that the imbalanced prices do actually represent equilibrium, e.g. imagine tariffs are 100,000% and well-enforced. In the real world non-zero exchange costs are the reason why price differences across countries for identical goods aren't just immediately arbitraged away.