2000 lira about 10000 is more than enough for 10 days considering that you will use public transportation not taxi... from Airport to Taksim or any area in between Galata saray etc ask about Havatas Bus .. and in the return as well ... Metro is the secret and install Trans app in Turkey .. it will guide u .. how to move from place to other .. will give you info about buses by no and metro by lines everything is available on the app .. as for food 100 .. I estimated 100 lita per day but u can make less if you eat shawerma from street shops like here but taste and quality is different .. enjoy public places and avoid back and side street ,, Have a safe trip..