* -Not Applicable-
It would be different if they were worded like that :
Expend: You may sacrifice a card in your hand or discard pile.
Then, if you have sacrificed a card this turn, gain an additional X combat.
That way, the sacrifice would not be tied to the first ability the way it is on the card.
There is actually a card like that in Star Realms, so that's kind of proving the different intentions of the designers