Its not the same cost, you are comparing the upped of this card with the unupped of the sundial to claim same-cost, incorrectly. It is +1, i.e. double cost for un-upped and also +1, i.e. infinite (1/0) times more expensive than sundial for upped version.
Of course, a cost increase might still be necessary to balance the card, I'm just pointing out that your starting position is wrong when you say its the same cost.