(Given that First Family is both green and blue, X is probably at least 2.) Flame On
Of course this is different if you can sell several cards in the same order, but even selling a $2 playset isn't that appealing with $0.50 off the top
You can see an overview here: 90% (4th card), 60% (5th card) 5% (4th card), 20% (5th card) 1.666% (4th card), 6.664% (5th card) 2.572% (4th card), 10.288% (5th card) 0.5% (4th card), 2% (5th card) 0.222% (4th card), 0.888% (5th card) 0.04% (4th card), 0.16% (5th card) So, if you open 1,000 boosters, there should be one to two cards of the crown rarity
Because you generally only have a few creatures, since you are focused on just one, it makes you susceptible to attacks from the rest of the players in the game
PS Platinum Secret Rare QCSE Quarter Century Secret Rare Blackwing - Vayu the Emblem of Honor X DARK Level 1 [ Winged BeastTunerEffect ] ATK 800 DEF 0 This face-up card on the field cannot be used as a Synchro Material