We have that system down here in New Zealand. However we have only two supermarket chains and a near monopoly for many consumer good and building supplies.
You can buy New Zealand produce around the world for less than it costs us in New Zealand. So going for a meal costs what it says on the menu and no more, but that cost is steep.
I don’t think inclusive pricing and the cost of goods are necessarily linked, there are many other reasons goods and services could be more expensive in NZ.
Oh there are, rules around employees, consumer guarantees act, acc levies and various other things. But it seems unlikely that have just 2 food suppliers isn’t a root cause of food price issues.
It looks like New Zealand charges a 15% VAT which is applied when New Zealand residents buy anything in Europe but not when New Zealand goods are exported, maybe that could be where the cost is?
There is VAT when you buy in the UK too though. New Zealanders pay way more. It's seems to be 50-100% what those in the UK pay for groceries, though this varies depending on how you measure or what you read.
You can buy New Zealand produce around the world for less than it costs us in New Zealand. So going for a meal costs what it says on the menu and no more, but that cost is steep.