Isn't the cost of living there (eating) cheaper than in San Francisco ?
I am from Austria (Western Europe) and have been in Istanbul some weeks ago. If you are not going to eat at tourist traps I had the feeling that eating was cheaper than in Austria.
Buying clothes and shoes was cheaper than in Austria too - so I guess the cost of living there is less than in Austria.
Beer and alcohol is / can be pretty expensive - but other than that I thoughts it is pretty cheap there (as a tourist)