Following a lot of discussion on here before we went in June, I wouldn't take anything except a few Lira, the £10 for your visa and your bank cashpoint card. You will get a better exchange rate over there and you only cash what you need.
My Oh and I spent approximately 2000ytl when we were there BUT
we were self catering so all meals had to be paid for which included 2/3 courses most nights.
we hired a car for a week at a cost of 160ytl (and with fuel at £1-35 a litre that ate in to the budget)
we went on an all day boat trip
My OH went to Ephysus for a day trip ( I was in Rhodes at the time but I budgetted seperately for that trip - and I was amazed at how much more expensive it was in the Euro zone compared to Turkey)
We both had pedicures, I had a Turkish shave, OH had a manicure
We bought presents
MY OH drinks diet coke (which was more expensive than the Efes beer!!)
AND - we had a brilliant time and can't wait for next year.
So I think you should be OK, Rob
Dave