Banishing 3 or 6 cards from your Extra Deck face-down is the cost to activate this card.[1]
This card's effect finishes resolving by drawing a card(s). (The part of the effect that prevents you from drawing cards with other effects for the rest of this turn is applied immediately when this card resolves.)[1]
A: When activating the effect of a Normal Spell Card that was sent to the Graveyard by the effect of "Destiny HERO - Diamond Dude", you do not pay the normal activation cost, so you are not able to activate the effect of "Pot of Extravagance".[3]