I'm definitely going to see Tiesto and hopefully AvB will have a gig during our stay.Pacha is very busy every night because of the ever expanding vip area making the rest of the crowd very cramped. My advice to you regarding Amnesia would be to go to Cocoon or Armada. They are not as overcrowded as Cream. Tiesto on a monday at Privilege is not to be missed this year either so I would think about going to that one.
You shouldn't have to spend 60 euros anywhere if u buy a pre-sale ticket in advance. If you buy a ticket on the day for the party you are going to you should expect to spend between 25-50 euro. You can buy tickets in many bars and shops across the island.
Many thanks!