I don't think this makes any sense. If this were true, payday loans would be the lowest interest loans, and ghetto grocery stores would have the lowest prices.

The more money you have, the less desperate you are, the longer you can wait to make a purchase, and the more storage space and capital you have to enable you to get the ideal price/unit bulk rate. I don't think surveillance pricing will affect the moderately rich at all. It will only target the poor.

They will know that you have no bread left in the pantry, no car, two children and no other grocery store near you, and you will pay convenience store prices.

edit: Hell, they'll know that you have $10 left, so you can afford it. They'll know you have a history of taking payday loans when desperate, so they'll raise the price even when you can't afford it, and sell your identity to a payday loan company. The payday loan company will pay a bigger premium for you because they know you have a propensity to default.