If prices stay the same and are rounded, maybe not. But I can easily see Tesco (et. al.) making the 13p tin of value beans 20p and so forth.
Rounding has been policy here (Ireland) for 5 years and is also used in some other €uro countries. Prices are rounded both ways, 1,2,6,7c rounded down, 3,4,8,9c rounded up. It works well and there was no obvious price increases, although that was probably more to do with the competition from the German supermarkets who really turned the tables on Tesco and the two Irish chains who were very expensive beforehand. I wouldn't be surprised if the big players have calculated how to gain more than they lose from rounding but they are at that constantly with everything anyway.
Looking at my grocery bills, it is not the case that most products are priced to 5/10c, by far the most common price across Tesco, Aldi and Lidl is x.x9, the lure of making stuff seem cheaper wins, the same as always.
Rounding is voluntary, all the chains opted in pretty quickly only some random indy shops still give 1, 2c coins in change these days. It has made a huge difference in the amount of useless shrapnel going around though. My mother was an avid collector due to never paying with lower than 50c coins, she went from filling jars with the stuff to barely ever bring them home.
Discussion of the fifty pound note reminds me that the five hundred euro note was withdrawn a few years ago - large denominations of currency can cause problems
It hasn't been withdrawn, ECB did not introduce a new series €500 along with all other denominations so new €500 notes are no longer being issued, however current notes (and there are a LOT of them) are still in circulation and fully valid.
Unlike British currency, despite being superseded all original series € notes remain valid indefinitely.
The obvious appeal of such high value notes in a major currency to organised crime was brought up at the time of the introduction of the € but certain countries who had a love of large denomination notes (Germany) pushed it through.
I just think that there'd be too many people upset in the UK if you tried to force people without debit cards to pay more for products than people with cards - it'd be a two tier system that penalises the poorest in society who'd end up paying higher prices.
Or are you saying that someone with a card would pay $29.97 for three items (i.e. three times the actual price) but someone paying cash would get it marginally cheaper (since the shop would round the seven down to the nearest five)?
That's exactly haw it works here and nobody has been thrown into the workhouse as a result, it is really not a big deal for anyone bar a handful of professional moaners, even that lot seem to have lost interest after a year or so.