Submission

Woodsman | Action - Reserve | $4
+1 Buy
Put this on your Tavern mat.
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After you play a card, you may call this to choose +2 Cards; or gain a card that costs up to $4
Heirloom: Lumber
Woodsman can be called immediately for a more expensive workshop that gives +1 buy. Or you can treat it like a +2 cards +1 buy which would be weak silk Merchant. If only you could line this card up for when you need it, so you can gain $5s with it. Well, you can! The power is you can choose to delay calling the card. You can choose to keep it on the Tavern mat to save a later turn, like a coin of the realm for cards. Or, you can wait until you play a Lumber, and now you can gain a card costing up to $5.
This card can be called in your Action, Buy, or Night phases. And this card can be called when it's not your turn. Thanks to Menagerie, there's a ton of cards that can be played out of your turn, like Black Cat. Good thing that both the actions you can take when you call it are easily trackable even if it's not your turn.
The card has to cost at least $4 because it is strictly better than workshop.
As always, open to feedback.
Edited to incorporate Gubump's feedback below moving from before -> after