Currency Exchange rate in shop

I'd like to ask if there is any way to change currency in shop, or adjust exchange rate to more real values? I'm located in Poland, as of today 1 USD = 4 PLN, 1 EUR = 4.3 PLN while in shop 10$ bundle costs 60 PLN - which is 50% more. I would gladly buy more packs if the value would be better adjusted.