after forking out that much there would be anything spare in my purse too tip..............If the service is excellent maybe just a few lira

I would only tip if I got good service, the culture in Turkey seems to expect tips even if the service is poor and inadequate and I certainly wouldn't want encourage that. Good service deserve rewarding though. I agree not to use pound coins as they then have to ask tourists to swap 10 for a note which a lot of folk dont want to do as they dont want to rattle when they go home.