If you go on the Turkish Airlines site they have a range of airfares, based on availability. If you book early enough you can get a seat for as little as 69 YTL. As the seats are sold out, they X out the lower fares and the the price increases up to as much as 159 YTL.
See the example below. The black X's indicate that those fares are no longer available.
Howard [ Just Imagine ] 25-Feb-2007