aileron i do agree with you that expat numbers are not even close to EK but if you are saying that Istanbul is an expensive place, i would say that you haven't seen Europe or Dubai. You can live in a decent house with 1000-1500 euros per month in Istanbul. It is more like 4000 euros in Dubai. Eating outside at a mid level restaurant for 2 people dinner would cost you 50 euros in Istanbul. In Dubai it is at least 80-100 euros and in Europe it is like 60-70.
Salaries for FO in TK is like 5500 euros and that is less then middle east. However there is the sandpit and Istanbul. The choice is there. However i strongly recommend for the married pilots to consider Istanbul over Dubai. Because for 5 months your wife won't be able to go outside and that may cause some problems if you know what i mean
And about the english part. That is right that TK is a little problematic about that. However if you are a captain, most of the time you won't have any problems. Especially if you are on wide body in TK you will have 3-4 flights a month with 10 consecutive days off. Which means approximately 60-70 hours of flight maximum. Which means you have free time unlike EK...
Those are my sincere observations, including opinions of many friends flying for TK.