I have a debit card (mastercard from Sydbank, Denmark). I'm gonna use it to withdraw money from ATMs in Turkey. I asked my bank but they said it's up to whichever Turkish ATM (its bank) I use. Any estimations as to how much in fees I'll be paying?
Although not unheard of, it is quite uncommon that ATM operators charge you for using foreign credit or debit cards and after using several different ATMs in Turkey, I've never experienced that Turkish ATM operators do so.
Your bank however (Sydbank) charge 2% of the amount, minimum 50 DKK for cash withdrawals abroad. I don't understand why your bank couldn't (or wouldn't) provide you with that information, but you could easily have found it in Sydbank's list of charges. In addition to the withdrawal fee, some banks use poor exchange rates when converting the foreign currency, causing you in reality to be charged with an additional hidden fee. I cannot tell however if that's the policy of your bank.
Not sure, but I heard that Garanti offers the lowest fees. Because they started internet banking system which is successful and they have been improving an application to attract tourists. So I think maybe for a short time but they offer low fees. I may be helpful to check it.
I can only speak from my own experience with austrian debit cards.
I payed between 3EUR and 3.50 for checking out 500-600 TRY.