Sometimes, like with Rona, Herald of Invasion, this results directly in combo value, but each legend makes Mox Amber more appealing
I suggest doing research of each grading service's qualifications of what a "perfect 10" is and how they evaluate each card
Even with a similar system, duplicates of rare cards may be a bit of a letdown unless players are using them in Pokemon TCG Pocket decks, but at least they could provide a bunch of pack points for players to use on other cards
Iron Knight of Revolution is another high-value tournament-style card that appeals to collectors because of its limited release background
The only downside is that while you control no tribute summoned monsters, this card pops itself during the end phase
Sometimes, you just want to play the game with your friends, so this error can feel like the worst