I'd say it probably depends where in Turkey, but we recently spent 2 weeks in Turgutreis (which I think I've read is more expensive than some other resorts) on a B&B basis and we spent slightly under £1000 between 2 people on food and drink.

We had a bottle of wine every evening (which is not really cheap, usually between £8 & £12), ate out (heartily) lunch and evening, beers on the beach, beers or G&Ts as we came off the beach etc so we didn't stint ourselves at all.

You can eat out much cheaper by eating doner kebabs, pide etc.

2 beers, 2 pide (Turkish pizza) cost £8 so you can spend as much or as little as suits you.

Beers in bars were anything from 3TL to £5TL, so most expensive was £2 for 500ml of Efes.

Actually, I worked out that, taking the cost of our flights, accommodation & spends into account, we spent around £50 per person more than if we'd have gone to one of the AI hotels.
To me, that £100 was very well spent as we ate and drank what we wanted, where we wanted, when we wanted and visited whichever beach we fancied.

NB
I guess it depends whether you want to go clubbing every night. We don't.