The best way is to grab yourself a fast and strong sweeper (Like Mewtwo or Deoxys-A), and then storm through the Pokémon League with an Amulet Coin. With the right Pokémon, you can OHKO every Pokémon they throw at you without a problem (After Kanto, where their Pokémon are over level 60). I let my mom have some of my money, so I always have some in reserve if I run out.
|