How much should i budget in spending money on a weeks holiday in Abu Dhabi?

I am due to visit family who live and work in Abu Dhabi. I will be staying with family in their apartment, using their beach club and their second car. How much should I budget for in spending money to account for lunch (daily), 2-3 evening meals out, soft drinks and a little bit of gift shopping etc ? I don't know what to expect to spend and don't want to embarrass myself nor my cousin.