If you played your cards mate and were dedicated thenyou could go clubbing every night of the summer! I worked out there for the summer last year, went with £800 and got a job working for one of the big club nights. This meant I got all my passes for the clubs (or glist) and finished work in time to go to a club after work. I even had two days off a week which allowed for big sessions. (most jobs with club nights give you at least one day off).
I think I stayed in less than 10 times the whole season, granted I nearly died
but I was loving every minute of it so it wasn't a chore!
If you've got the stamina and you get out there at a decent time (end of May really) to get to the interviews, and u get the job then you're sorted. The only jobs where you really don't get time to do much clubbing IMO are bar/restaraunt jobs and all the west end bar jobs, steer clear if clubbing is your priority!
Another tip (though you prob don't need me to tell you this): Make friends with people, as well as generally increasing the amount of fun you have on the island, also means saving money on club tix through glists etc! It helps if you work for someone THEY want to be on the glist for too...
DO IT!!!