That'll be $100 per day for food, accommodation, sightseeing and transportation. $600 seem like a lot of money but Turkey isn't as cheap as it once was. I'm sure you can probably get by on $600 but if you're planning on doing a lot of sightseeing tours, they're pretty pricey. You have to remember that things are more expensive in Turkey, if not more expensive than America nowadays so unless you plan on doing lots of walking and not much sightseeing tours, you'll need to allow at least $200 a day.