To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of Danitha Capashen's last ability)
The point is to make Gandalf huge and swing with him, and it doesn't really matter how
I would be surprised if these cards arent in the top ten commons in Guilds of Ravnica , and to be honest, they both could be in the top five
However, if you want to complete the set, it can be a bit of a trek
When the last is removed, sacrifice it.) When Crack in Time enters the battlefield and at the beginning of your precombat main phase, exile target creature an opponent controls until Crack in Time leaves the battlefield