You are right everything had changed. these days exchange rate changes a lot, even 2 or 3 times a day, It was really hard for me to check the price before all payments, and sometimes specially in far areas it was somehow impossible to do so.
I didn't know about tourist cards then but when I returned home one of my friends told me about Daricpay and another tourist cards which you can buy them in advance and use them as a national debit card. I'll definitely try them for my next trip.