Is 5 life the right amount? Barring shenanigans, it only allows three activations without killing you.

Seems kinda high, even. Admittedly, looking at Lich and getting the exchange rate as 1:1 is probably not really valid nowadays. But it seems to me there are plenty of ways black can draw a card for less than five life; and drawing a card is much more useful than only paying for discard costs.

Given the nicheness of it, I'd be tempted to make this: ­:The next time this turn you discard a card as part of a cost, that part of the cost is free. (Or maybe: take it back into your hand afterwards) And have no life cost at all.

Yeah, that's a lot of ouch. What card would this card brake if the life loss was 3? Because I'm pretty sure this would still be a bad card with Wild Mongrel, Frantic Search or Razormane Masticore. I say go for 2 life, unless you can think of a few cards in modern that it can really break. For this casting cost, at Mythic, I'd expect "Goblins you control get +3/+0." This card's only going to be important to a limited selection of cards... it might as well reward you well for playing that deck.

Oh. Maybe this isn't as breakable as I originally thought.