Gitaxian Tides

Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost plus {1} for every 2 life you spent to cast Gitaxian Tides. (For example, if the card's mana cost is {1}{u} and you paid 2 life to play Gitaxian Tides, it's flashback cost is {2}{u}.)
Don't judge a plane by its oceans.