Its free if you have a sunbed / food etc.  I don't know about just turning up for a drink, I assume thats free too.

Hi thanks for reply i always go to Ocean Club as its on me doorstep but for a change will try Nikki when there in 2 weeks cant wait

hey the last time i was at niki beach it was like 150 euro for a sunbed and i think it was like 25 euros for lunch, but there is no entrance fee, to pay so its up to you what you want, it was sooo nice tho on the sumbeds

hope it helps