I think the personalized stuff is a bit on the creepy side, but I can't articulate a specific ethics issue. The supply/demand stuff I actually support.
Take for example bread and milk. The store sells them at cost or maybe even at a loss, because if they get your feet in the door you might buy some 25% markup breakfast cereal or steak.
Well here's the deal. Your staple food might be bread. My staple food might be rice. Now the store can give me a better price on rice than what you pay. If you rarely buy rice, what do you care?
I am probably more financially frugal than most people here, I won't gp out of my way an hour plus got a better deal, but I do just stock up on things when it is a good deal
my local grocery store stickers all their items between 40-65% off depending on how much they think they can get away with charging for it to sell it before they have to throw it out, so I get a lot of heavily marked down stuff and just freeze it
We also have pretty good consumer protection laws already anyways, since if the price you ring up does not agree with the price it was advertising, the store is legally obligated to give you the item free, or 10 dollars off, whichever is less money
so if they were changing it, and they were called on changing it, they would have to give it for 10 dollars off legally right now, the way the law is written