I'd say if your on half board,and you are sorted for brekky and tea, then youl need the following:-
About €50 to get stocked up on booze and water etc for your room for the week
About €30 a day- just to have on you so you can catch a water taxi to diff beaches, maybe buy the odd bottle of beer etc if you are using other hotel pools,and for the odd snack
About €50 backup in case you need a taxi back from somewhere
For the club nights - say 4 tickets, if you can get good deals - just look around - and a lot of people say try the pussycat bar - which isnt far from the egg - say €120
For the club nights spends - say €40 a night (€160).... be prepared to only get a few drinks fromthat - so go with plenty of drink already drunk
All in all - it comes to around €600 - Id take €700 as there will always be those impulse buys - sunglasses, lilos, new shirt for a night out.
£700 UK pounds will leave you sorted