Catching all the Pokémon in the Sinnoh region is one of the big goals in Pokémon Brilliant Diamond and Shining Pearl. As you progress through the game, the normal Poke Ball may no longer be able to do the trick. So, you will have to buy other types of Poke Balls to increase your chances of catching a Pokémon.
Quick Balls are one of the different types of Poke Balls and are unique in how they work. They have a higher success rate if used at the beginning of a wild encounter. Therefore, they are great if you find yourself in a battle against a low-level Pokémon and want to capture it immediately without risking knocking it out in one hit. Players can get 12 Quick Balls if they purchased the game before February 22, 2022 and redeemed their code through the Mystery Gift. However, once they are sold out, that type of Pokeball is not easy to come by and can only be purchased from select Pokemarts.
You can get Quick Balls in Pastoria City, Celestic Town, Canalave City, Snowpoint City, and the Pokémon League. They will cost you £ 1,000 each, so be sure to save up if you want to buy a ton.