If you're taking the debit card with you anyhow, I would really recommend you use it to withdraw sterling from an atm. You'll get a one of charge from your bank - check with them, on our accounts it varies from £1.50 to £3. This will be more than compensated for with the better exchange rate you can get for your cash, or to get a better deal paying with sterling.
Check what your bank exchange rate is likely to be if you do want to use your card and pay in lira, it's often quite poor, so as well as a transaction charge, you could be losing out quite a bit if you're planning to use it a lot. We bought diamonds in May and asked what was the best way to pay, whilst they were very happy to take whatever means we had, sterling cash was better. BTW, if you want good diamonds from a great jeweller, try Vidat at More Jewellery next to Avlu 1 - tell him Andy and Nicola sent you
