In Pokemon FireRed and LeafGreen you can't open a gym.
Battle more trainers and beat them.
The code for infinite money in Pokémon FireRed is 74000130 03F5820257BC 423F,74000130 03F5, 820257BE 000F. This code has been tested and verified.
beat the elite 4 alot
it give a lot of heath for not a lot of money
You get money by selling items or beating other trainers in a Pokemon battle
charemander
Ace Trainers Dragon Tamers
To sell for quite a lot of money
This is the Master code that must always be on. 9820F6AE820351F0DBDF70D1407403064659This is the money cheat for Fire red.7B9BF36F3E54057F598C429E67506BC45CBD00B6F1903AF7CC4F8C630144A30F4BE92B374EA3D5281636424F078E7AD10FC3F521963E832B1FF442CB6FA755041618C70BBAD883D3C5B56DEED1B8
If the holder of the Amulet Coin enters battle, the money you get from defeating the trainer is essentially doubled. It is useful if you want to restock on money in a quick way.
pretty much every where.