[theqwxas]

I find these types of maps fascinating. For people wondering what would this map look like if we were not limited to the USA and Aldi: https://www.numbeo.com/cost-of-living/gmaps.jsp?indexToShow=...

There are a few larger categories (groceries/rent/etc.) rather than individual items.

[djdeutschebahn]

There exists data for websites of groceries in german speaking countries. But I think without location coordinates of each supermarket.

This one tracks all online prices of all the austrian grocery brands https://github.com/badlogic/heissepreise

Related thread on hn: https://news.ycombinator.com/item?id=37533633 But didn't took of.

They also gathered some historical data and competed with an government initiative to establish a price comparison app.