Surprise your audience with a jumbo size copy of their chosen card. We think the custom made gimmick is worth buying. Although it's a nice give away, consider using it for the surprise effect only, then continue by saying "this one is too big to use" , take it back and push it aside. During the unfolding of the Jumbo card there is plenty of time to execute a mercury fold with the card that was initially chosen. Make that one appear from any location , e.g. your mouth, wallet, shoe or even the spectator's ear.