this is interesting, as I have always fancied going in the VIP at amnesia... not so bothered about anywhere else.
Where do you pay the extra 20 then? would this be possible at nights like Matinee or Cocoon?
buying online means you've got your ticket sorted and you get in the quickest way possible.
nearly all clubs have a separate internet ticket list queue.
as for VIP. at cream for example, you pay 20€ (i think) more and this gives you access to the upper part of the club, especially at amnesia, it's worth it.
When I was at Amnesia I just went up stairs.. are you talking about another section?