Greed is a trade-off gear perk that raises the Pesos you loot but lowers your ammo reserves. It suits money farming more than big fights.
You collect more Pesos from loot, but you carry less spare ammo. Long gunfights will drain you faster.
Only for dedicated money runs. Peso Accountant is the safer money perk for normal play.
Observant lets you grab ammo and Pesos from further away, which offsets the smaller reserve.