I can't say that I have ever found taxis, with very few exceptions, anything less than expensive in Turkey which is not surprising considering the price of fuel. Those exceptions happened when they were returning to "base". Then, if you are waiting for a dolmus, they'll slow down and shout a low fare at you just to defray the cost of getting back to the stand. The last time this happened to us was when we got dropped off from an intercity bus in Gunlukbasi and waited, with our luggage, for a dolmus just past the "uc yol" junction to Calis. Seeing us the driver shouted "5 Lira Calis!". Even a penny-pincher like myself couldn't say "No" to that. I guess this isn't the usual rate.