>That's called "the consumer price surplus". It's one of the major reasons that market economies are better for everyone than command economies. And it's the antithesis of price discrimination.

I'm not denying this exists, just pointing out your Reductio ad absurdum is absurd and fails rhetorically. If your point is that without surveillance pricing legislation, people selling us essentials will milk us for the last dime we have, that simply isn't happening today.

> It's not that price discrimination should be illegal, it's that successful price discrimination is a strong symbol of monopoly

This isn't obviously true. For instance, airlines engages in intense price discrimination, with different fare classes, discounts, and changing princes per day, yet the industry has famously poor margins - the exact opposite of a monopoly. Same for games and movies (they get heavily discounted after release), and while you can argue the copyright system gives them a monopoly, it's only on that particular work. There are plenty of other games or movies to choose from.

> If your point is that without surveillance pricing legislation, people selling us essentials will milk us for the last dime we have, that simply isn't happening today

https://en.wikipedia.org/wiki/Bread_price-fixing_in_Canada

They don't even need surveillance pricing, they already try to do it. This wasn't some 1920's scheme, this was very recent.

It seems to me that the level of surveillance we're talking about, with dynamic pricing, would make it both easier for them to gouge and harder for price fixing to detect. Win win for slimy capitalists.

Edit: so maybe you're right that given the opportunity, no one is trying to milk you for literally every dime you have. Still, we should probably not allow businesses to milk the average person for every dime they can get away with, either. That's still bad for society.