Paying with threat is buying with a credit. You will pay it back with effects lowering your menace, or will accrue debt interests by having enemies engaging you. My rule of thumb is that 1 threat = 0.5 resource if you play , 1 otherwise. So for 0.5, you add 2 to 3 of with most decks turn 3. With a deck built around this, you will add +5 . With a credit, so in the same spirit Deep Knowledge or Legacy of Númenor, we know how much tempo it gives.

It's pretty awesome.