When I was at Space in July you had to choose what drink you wanted when you bought the tokens. So for instance 10 water tokens was €60 (which for Ibiza is almost reasonable) but you couldn't then use the tokens for anything else. There was a limited selection of options - I think you could go for beer, long drinks, vodka redbulls and a few others perhaps but each selection had its own price list. The best deal was always the 10 drink price of course and then I think you could buy 5 and maybe 3 as well but the smaller the number of tokens the less good the deal. You also couldn't swap a long drink token for a vodka redbull. I should have taken a picture but in the end me and mate decided to share the 10 water tokens and it worked out pretty well.