Board Thread:Game Discussions/@comment-84.105.32.169-20180808094209/@comment-27862737-20180808205029

It depends on the server you are on (iOS Global, iOS EU, Android Global, Android EU) and the element combination in question. In other words, adjacent element combinations (like A/W or W/F) are generally more "expensive" than non-adjacent (like A/F or W/S), so that also has a bearing on the number of gems needed. Raids also have a different "cost" involved as opposed to Guild Wars.

Best to ask your GM/guild mates or alliance for more details.