Some market cards have beneficial effects if you destroy or discard the card after playing it. Other cards (player or nemesis) will require/allow you to destroy or discard a card(s). Destroying or discarding Card A to pay for Card B's effect does not trigger any of the effects that would have been triggered by playing Card A.
Example: A player destroys a copy of Bottled Vortex (Destroy this. Destroy up to two cards in your hand or discard pile. Draw a card.) to discard the Agony Field power (To Discard: Destroy a card in hand that costs 2$ or more.). Because Bottle Vortex was destroyed to satisfy the power card discard rather than by playing the Bottled Vortex, he does not destroy any additional cards or draw a card.
