To be honest, I find it hard to believe that free market forces would not eventually have an impact over time so perhaps you are a bit too strong with your use of the word "never". This would be equivalent to all hotels raising prices 20% all at once overnight and all of them enjoying higher profits. Someone is bound to reduce prices, for example by 10%, and get a greater volume of customers as a result at still profitable prices, even better prices than before the currency crash. Then others start to follow to avoid losing customers and soon you have a perfect example of competitive market dynamics if and when it happens.