Minimum Ending balance required for Visa

I am Naushad from  Karachi Pakistan. I have to go Turkey Istanbul for visit to my business friend, she already send me the invitation with stay,meals and health. The visit is also for business meetings and deals. She also invited me in her Son marriage ceremony at 24th october 2015 and i also like to spend my time to see istanbul and other places.All stay and tour expenses for 2 months will be spend by my host its also mentioned on the invitation letter. My all documents is ready and completed .But I want to ask that how much ending balance I need to show in my bank statement to get visa.I am very confused and worried.kind mensioned the amount in U.s dollar.