How do you get more money in Pokemon fire red once have beaten the trainers?

1. Sell items at the Poké Mart. This is the most basic way to get more money in Pokémon FireRed. Simply sell any unwanted items you have, such as Potions, Poké Balls, and TMs, to the Poké Mart for cash.

2. Win the lottery at the Celadon City Department Store. Every day, you can purchase a lottery ticket at the Celadon City Department Store for 1,000 Poké Dollars. If you win, you can win a prize of up to 100,000 Poké Dollars!

3. Find hidden items in the game world. There are many hidden items scattered throughout the game world, such as Nuggets and Pearls, which can be sold for a lot of money. These items are often found in out-of-the-way places, such as behind rocks or in tall grass.

4. Train your Pokémon and become a Champion. As you progress through the game and become a Champion, you will be able to challenge the Elite Four and the Pokémon League Champion for increasingly higher amounts of money.

5. Participate in the Battle Tower. The Battle Tower is a challenging gauntlet of battles that you can find in the Pokémon Tower in Lavender Town. The further you progress in the Battle Tower, the more money you will earn.

6. Buy low and sell high. You can also make money by buying items from one store and selling them for a higher price at another store. For example, you can buy Potions in Pallet Town for 300 Poké Dollars each, and then sell them in Vermilion City for 400 Poké Dollars each.