I think the cost can be lowered a bit. It may get you a card, but it's drawing a card for much more than ore cards already in game, and then you still have to play the shield (assuming that was the purpose of having this card). And since this draw isn't repeatable like hourglass, you don't have to overcompensate cost. Even though it's letting you, (possibly/probably) draw target card, you could argue that that part is so important or crucial that it demands a higher cost, but a shield is hardly as game-breaking as, say, getting your single creature of an OTK (but if you know of any shield OTKs, do let me know) (and I don't mean the opponent killing itself).
So for that part of the card, I feel it's cost could be lowered by one. As for the doubling of hp, because it affects the opponent's creatures as well, I think that part is balanced. You're probably not going to be running a heavy CC deck and this at the same time.