Money Farming Guide for Pokemon Brilliant Diamond and Shining Pearl
In Pokemon Brilliant Diamond and Shining Pearl (Pokemon BDSP), you can purchase a variety of usable items, Technical Machines (TMs), outfits, stickers, and avail of useful services using money (Poke Dollars). Note that it is entirely possible to get by the main story without farming, though you may want to have as much money as possible by the end of the game for the sake of completion.
Amulet Coin
The Amulet Coin is a held item that doubles the prize money you earn after defeating other Trainers in battle. You can find the item on the north side of Amity Square in Hearthome City.
Money Farming Procedure
You can easily farm money after you have beaten the Sinnoh Pokemon League Champion (Cynthia) and registering your name in the Hall of Fame. Below are the steps to earn money easily during the post-game stages.
Capture Heatran.
Once you have obtained the National Pokedex (National Mode) from Professor Oak in Pal Park, head to Stark Mountain and catch Heatran. This will allow you (Trainer) to be strengthened to the maximum.
How to Unlock the National Pokedex
Defeat the Socialite, Gentleman, and Lady Trainers at Sinnoh Route 212 (Near the Pokemon Mansion).
Four trainers (Socialite, Gentleman, Rich Boy, and Lady) all grant you a hefty sum of money when you defeat them. Be sure to have the Amulet Coin equipped to double the prize you get after winning.
Defeat them again in Rematches Using the Vs. Seeker.
Use the Vs. Seeker to go up against the four trainers mentioned to win even more money from them. Note that their Pokemon will be stronger in the rematch so it is worth bringing your best Pokemon to take them on again.
The Vs. Seeker needs to be charged again (which takes about 100 steps) before it can become usable. Try to do something else while going around the Sinnoh region until it finishes charging.
If you find yourself struggling in the rematch against the four trainers mentioned, try to level-up your Pokemon by taking on the Elite Four multiple times.
I don’t understand why Heatran is relevant.
This ^