Game: Ruby AXVE Firered BPRE / Emerald BPEE
Yeah, today will be this little thing.
Offsets:
Ruby: 0x052F4C
FireRed: 0x054B60
Emerald: 0x0845BC
You see that little B8 0B 00 00 in those offsets? Reversed we get 00 00 0B B8 (000BB8).
BB8 (HEX) = 3000 (DECIMAL)
So you just have to change that value to whatever you want to be the initial money amount!