This is what I came to the comments to gripe about this whole thing. Yes, they can play some games and probably will, but consider: People will be watching. They do this and you bet people will track this crap and post about it. The blowback will be huge.

If they're stupid enough to try this, it will not last. lol. You can raise prices over the long term, but fuck around with short term prices people can see changing for no good reason? Yeah.....

And on the "personal pricing" - that's written by someone that doesn't understand how barcodes work.

But I'm sure they will try to play some games with it.

“It was $2.99 when I picked it up.”

Watch a product for a minutes, clock the lowest it displays in that time, run in and grab it, “It was $2.99.”

Repeat for all 30 items in your cart just to annoy the store.

The solution of which is that you change the tag before you change the actual price if it's an increase, and the price before the tag if it's a discount, with a long enough delay. That's what they do with gas pumps and the advertisements here in Finland.