For EXTRACTED auto/user saves
This is a tutorial on how to mod your Far Cry 3 money at the start of the game.(2.147.474.647 @ start and 2.147.483.647 when having all wallet upgrades)
The values are written in Intel-Long
Extract the usersave from the CON file with Horizon.
Open it in any hexeditor.
For the wallet capacity you should search for the base value,which is always 1000.(if not edited before,derp)
Meaning you ALWAYS have to search for E8030000 (Check image for details)
This will stay the same even when upgraded your wallet.Upgrades are stored aside from the base value.
There should be one instance only.
I also came across a save which had 2 instances for E8030000.In such case you have to use the one that's before your current value.
Set that value to D7DCFF7F which is 2.147.474.647.
This is because you have to leave room for the 9.000 extra capacity you'll get for crafting all wallet upgrades.
Upgrade 1 = +1000
Upgrade 2 = +3000
Upgrade 3 = +5000
Upgrade 4 = +9000
Next find your current value.(Check image for details)
Make sure you have atleast $700 in your wallet but over $800 will be better,otherwise it can't be found in some cases.
Set that value to The one corresponding to your amount of upgrades (You can only add as much as your space allows,so just look how many wallet upgrades you have)
Without Upgrade = D7DCFF7F (2.147.474.647 Same as MAX Wallet cap value)
With 1st Upgrade = BFE0FF7F (2.147.475.647)
With 2nd Upgrade = 8FE8FF7F (2.147.477.647)
With 3rd Upgrade = 5FF0FF7F (2.147.479.647)
With 4th Upgrade = FFFFFF7F (2.147.483.647)
That's all,there's no encryption/checksum or compression on it.
Just reinsert back into the con file and rehash/resign.
EDIT: For those who can't find their current money.
Just gather some more money and try again,I've also encountered numerous instances the money didn't show up in hexworkshop.
In some cases it still won't work,then you just have to play a little further through the game,there will come a point the current money value is findable.