Seriously though, how do they know how much gil is in your pocket? It's rather disturbing. Last thing I want to do in real life is go to a car dealership and the dealer's all like "You can buy this Camry for $2500. I see you currently have $2600."
Imperial credits I can understand since they're recorded by the army and are probably accessed via some sort of secure network that only the imperial army has access to. I dunno, I dunno.