Necromancer used to be my coolest setup on a card... Now I have only my Edicts left, but they are not thaaaaat amazing. There's also a Black Market Event, but well, it's just a Black Market variant. I do enjoy what Heirlooms do, but I'd rather use the existing ones than make up my own for mechanical reasons (and because I like most of them). So here's something off the top of my head:
Inventor, 4$, Action
+3 Cards
Discard a card. If it is an Action card: +1 Action.
---
Setup:
Each player adds 2 Inventions to their deck.
Invention, 0$, Action
+1 Card
+1 Action
Huh, that didn't turn out as cruddy as I expected.
Edit: Removed dumb double-letters caused by writing from mobile.