If I understand TFA correctly, what is going on, is that the grocer is going
* This person is wearing a suit, I'm going to charge double
* This is a regular that always buys the same thing every week, I can charge 30% more without breaking his routine
* This one is buying the ingredients for a recipe to do tonight, I can charge double more on one product because she won't want to go to another grocer just for one missing item.
Or in economic terms it is doing price discrimination to turn the consumer surplus into profit for itself. I think it's obvious why consumers wouldn't like that. Although they can also do "this one is a cheapstake with lots of free time, I have to offer a 20% discount to keep him coming"
* This person is wearing a suit, I'm going to charge double
* This is a regular that always buys the same thing every week, I can charge 30% more without breaking his routine
* This one is buying the ingredients for a recipe to do tonight, I can charge double more on one product because she won't want to go to another grocer just for one missing item.
Or in economic terms it is doing price discrimination to turn the consumer surplus into profit for itself. I think it's obvious why consumers wouldn't like that. Although they can also do "this one is a cheapstake with lots of free time, I have to offer a 20% discount to keep him coming"