Oh, the moneygrab doesn't end with getting the three collection cards. You then have to feed them Candies. 600 each. Now, occasionally Kurito gives some candies, so some people might have a big stack of them by now, though others might've fed them right back to Kurito. But, the other way to get these candies? Through the Cash shop, only available in Nutaku Gold flavor, not for Pero Coins, in batches of 200 candies. So, that's 3 cards, needing 3 batches of 200 candies each, makes for an additional 900 Nutaku Gold.