I have been to Turkey many many times and have never used Euros.
Even in the resorts served by Antalya airport which are very popular with other Europeans prices are also in £1s
Most things are priced in pounds,lira and euros because Turkey has holiday makers from other parts of Europe.Before all those countries changed to the Euro the prices were in shown in all the currencies used in Europe.
If you look on the thread Monies on January 15th,you will see the prices we paid in Icmeler last October.The rate when we were there varied between 2.38 and 2.53.The local beer Efes was being sold at 1 and 2 TL in many bars which depending on the rate was between 37p and 40p!
Today in a travel agents they were advertising TL at 2.32 to the pound but in Turkey today the rate is 2.42tl to the £.
The best rate is by using a Nationwide Flex card and they dont charge for using it in Turkey.
I cant remember where I read that the TL is expected to be 3 to the pound by the summer.
It is excellent value for money but its the people what makes Turkey special.