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lastly, the format note: you should add the "+" into the cost to signify you can overpay for this card.
Clear-cut good catch on the formatting.
As for balance, you propose a buff and a nerf, so do you think the card is too strong or too weak right now -- and if it's neither, why does it need to change?
I think the buy-in cost is too high - if you have $8, the consensus correct move is buy a province, right? (ignoring context about current pile position), and the power (five cards, play the cheap actions) too strong. A smaller version of each is more sensible. In general, the high buy-in cost is going to cause swing, with the rich getting richer because they can play it more often.
It's like the Familiar feelsbad problem - both players open silver/potion, player A can buy a familiar turn 3, use it turn 5; player B gets a copper, 3 estates, and the potion turn 3, can't afford familiar, and then it sucks to suck until turn 5 at least, right? meanwhile player A can hit them with cantrip curses and split the curse pile in their own favor.
This is doubly exacerbated if Magician is the only "village" in the game.
So to directly answer your question: i think the effect is too strong, and also i think it's priced wrong (esp. in consideration of its overpay effect).