[0] https://www.valuepenguin.com/average-household-budget#food
[1] https://www.ers.usda.gov/amber-waves/2020/november/average-s...
But I think it should apply to all larger retailers.
Yes, yes, you can offer a terrible service, stifle competition, ripoff customers and not make any money - all at the same time! Such is life in the local maximum.
OT I would take it much further: I want government to process all transactions and do VAT automatically. You upload the price of your jar of peanut butter, you upload my order of 10 jars, I pay though the government portal, the amount after taxes is deposited into the store's bank account.
Then we could do lame things like ration peoples liquor, the amount of weed they buy, increase the price of your 15th quarter pounder this week but also prevent people from buying all the toilet paper in all the stores. (why have such a convenient mechanism for foreign agents to turn a country into chaos?)
Besides getting rid of the slow, complicated, bureaucratic, expensive administrative burden of taxation and the fines that come with it it would enable very lame things many would oppose and they would be right to do so. That is, until rationing is needed for some reason. Then you have a robust system in place to do it.
I mean, I can easily buy all of the canned food from my local stores. Why would I leave any for you? I'm sure people would prefer it that way. When a real crisis arrives you'd really want to be spending your time on preventable side effects.
I'm not sure this would be true, at least in the United States.
WalMart used to have a tool where you could scan your receipt in their app, they'd compare prices to competitors and if they found a lower price, you'd get a rebate.
It wasn't that popular or successful.
Can't find much info online, but here's an old discussion on Reddit: https://www.reddit.com/r/Frugal/comments/2x9ajh/walmart_app_...
As stated other places in the thread, most grocery stores are super low margin overall. Especially on basic food items. Things like canned goods, basic cuts of meat, eggs, milk and the like were often sold at cost or even at a loss. Things that we actually had good margins on were mostly products where we had vertical integrations or special contracts with farms or factories - we were matching our competitors' prices, but at a better margin because we'd worked out how to pay less for the raw goods.
With all that in mind, I highly doubt how "disastrous" it would be to have a public price database. Sure, you could probably shave your pennies by spreading your shopping over 4-5 different stores because they're each slightly cheaper than each other, but you'd almost assuredly spend more in time and transportation costs to do that than you'd save.
What would cause the stores to lobby against it is that many stores, especially now, change prices on things pretty often. The CSV you imagine publishing to a government site is something that, as I recall, takes something like 5 hours to generate every night due to the vast variety of products across the company, and the fact that different stores in different areas may be pricing products differently or offering different coupons, or simply not stock the product at all. There is no one price per barcode universally across the company, so the outputted pricing list ends up being gigabytes of data.
Of course doing do would be disastrous for the supermarkets, so I can imagine they would fight and lobby politicians vigorously.