This is fine if they want to drop prices to shift more, but they can't increase prices while the store is open as they are not legally allowed to advertise one price and then sell at a higher price.
I was wondering about this - same problem the OP highlighted re: the price changing by the time you get to the till
one option is hand held scanners, though these have been around for a couple of decades so far and seemingly don't seem to be preferable to the existing self service tills else we'd already have them in all stores... a substitute for these however could be to allow people to use a mobile phone app
another option is the sort of system which they have in the amazon store, you just put the stuff in your basket and thanks to the wonders of machine vision it is automatically added to your shopping list - price changes aren't then an issue as your shopping is tallied in real time too
the last option is a crude one - you don't instantly update a price per say but you allow for a lag of say 20 minutes before it changes, so before a price updates you get the label to perhaps change colour and also state that the price expires at: 12:00... not ideal if you have queues at your tills/self service machines etc.. but I guess if the potential price changes are done at set times during the day under this sort of system then it might be feasible to try
I guess the other thing, in addition to reducing waste, is that you're implementing some form of load balancing with regards to your tills etc.. those unemployed or retired people who are price sensitive are incentivised to use your store at quieter times through the day... perhaps after 9am but before lunch or after lunch but before 5pm - so your busy times perhaps become a bit less busy and your quiet times become a bit busier - I don't know whether this would be preferable from a staff point of view but presumably the current system where a bell rings and people have to interrupt their breaks or drop whatever they're doing in the back isn't necessarily good
Reminds me of the old idea that went round some years ago that people who did on-line shopping from an Apple mac/ipad were shown higher prices than those who ordered from a PC
Might even be true!
http://www.ibtimes.co.uk/look-out-y...-shop-online-using-mac-android-device-1474431
on a related note.. one of those companies mentioned that attracted discounts for users at other sites actually did something else along these lines re: Mac users:
https://www.wsj.com/articles/SB10001424052702304458604577488822667325882
Mac users tend to be richer so they showed them more expensive hotels