Been here about a week now, we use the plastic (credit card) for most purchases and have just checked we have got an exchange rate of TL3.19. So things are looking good.
If anybody is interested we get our pounds sterling from the ATM at the HSBC with our debit card, there are no charges/fees for the transaction. We then get our lira through the money changers. We don't have a Turkish bank account. This cuts out charges/fees you get if you draw Lira with a debit card
Euros are also available at HSBC. I assume other banks also have ATM's where £'s and €'s are available.
DonM