If you have multiple powers that could apply, and they happen to have the same cost. you have to pay the cost for each power you want to use. For example, Ezren has the following powers:
On your turn. you may recharge a spell to examine the top card of your location. If you do, you may discard ( or recharge) a card to explore. You may recharge a card to add 1d4 ( 1d6) to a local check against a Magic card.
If you are playing Ezren and want to increase your chances of acquiring a Lightning Bolt spell by recharging a Lightning Touch spell from your hand, you cannot also examine the top card of your location at the same time.