Comment by milliams

In the UK we brought in a similar law and the shops were allowed to charge (if I remember correctly) 5p for the thin bags that were previously used or 10p for a stronger one. It wasn't long before they mostly phased out the thin bags and started raising the cost of the stronger bags, I think they're maybe around 50p now. They've also mostly moved back to bag-less delivery (if you get delivery). Anecdotally looking around the shop when I visit, most people are using the much stronger "bag for life" bags which costs (again I'm half guessing) a few pounds and are reused from one shopping trip to the next.