If you mean 'challenging' other characters, or glimmers, in play Steel and Ruby are good at challenging and can get benefits for banishing opposing characters during challenges
That means you dont have to buy them for a complete collection
Numbers-wise, Pokemon is far and away the largest and most lucrative media franchise of all time, beating out titans like Star Wars, Marvel, and Harry Potter
With the online prices varying so drastically, its probably not worth stockpiling Happy Meals just to resell the cards, but finding the holo Pikachu card could turn a $30 to $40 profit and selling any of the others could definitely cover the cost of the Happy Meal
The box contains 20 booster packs, each with 7 cards, for a total of 140 cards
For reference, the other five tokens in that Unglued group are the extremely common Red Goblin (29 sets, 14 unique art printings) and White Soldier (29 and 12), and the significantly less so Green Squirrel (4 and 4), White Pegasus (2 and 2), and Green Sheep (printed only the one time)