Burial Mound - "Lower the cost of the first card you play from your discard pile by one"

We played it that the 4 cost tactic Raise Dead would cost you 3 to use due to Burial Mound being in play. Now that I'm thinking about it, I'm not so sure. I'm thinking the cost of the unit is irrelevant...because your not paying the units cost, you're playing a tactic. Anyone have any insight on this?

So you were playing Raise Dead out of your discard pile somehow? The cost of the unit you are using Raise Dead on never matters, that's why people do stuff like discard Grimgor (somehow) to Raise Dead him for 4 and still get his ability.

Raise Dead would not be cheaper if you play it from your hand yet have Burial Mound in play.