Most of us have a red and blue bicycle deck. At some point a level of sensibility comes into play. Add two standard decks that almost everyone already has and catch heat for including them instead of cutting the price, or including them and charging more for the effect.
The wonderful thing the effect does not damage the cards and they can be returned to the original decks anytime for another effect.
I posted an abstract on the tutorial page of the first segments of the tutorial where Mickael digresses into relative, but separate train of thought where I believe the initial confusion occurs. I believe if you read through the abstract you will find his instructions make more sense and are easier to follow.