Comment by jcriddle4

A 10% drop in currency would in your example, assuming no cost of shipping oil, US would go from 3.00 to 3.30 at 20% drop would mean 3.60 and even a US currency drop of 40% only gets you to $4.20. The data on trade indicates that countries that cheat on trade have epic growth rates and countries that do the "free trade" have close to zero growth or even declines. The data indicates local manufacturing has synergistic effects that massively outweigh the additional costs to consumers. See economist Ha-Joon Chang.