I’m less worried about the idea that people are charged groceries based on income and more worried based on need.
Will the person who buys cigarettes twice a day pay more than the person who pays once a fortnight because it’s clear that they require it more? Will the shopper of the family of 6 pay extra because they don’t have the time or energy to drive to the next place that offers groceries without this system?
Introducing this based on income seems like a sugarcoating of something far more insidious.
The most common cheat is probably gaining money or experience, but there have always been pretty extensive mod menus for GTA Online with tools from invincibility to making your vehicles rainbow, to randomly causing other players to explode or setting hundreds of muggers on them.
In 2015ish, I used to cheat, other than getting rich, all I was interested in doing was making an indestructible chrome bus with smoke trails that I’d drive around picking up players in, to teleport us all to North Yankton and back like a tour guide.