That's an interesting question because there are actually two legally separate Aldi companies, Aldi Sud and Aldi Nord.

They divide Europe up by country so you'd have to get them to cooperate on that.

https://en.wikipedia.org/wiki/Aldi#Geographic_distribution

Which Aldi is North America?

Both, in a way: Aldi South is known as just Aldi in the US, while Aldi North owns Trader Joe's.

Ah, so that's why I can sometimes buy Trader Joe items in Dutch Aldi (Nord).

Data :) Not easy to get it at scale without APIs

Well, the Aldi online shopping site [1] is using an API [2], but it is probably not intended to be used publicly. You could try exploring it to see if you can query prices directly.

[1] https://www.aldi.us/online-shopping/new-aldi-grocery-website...

[2] https://api.commerce.aldi.us/

I believe there is already a framework for this, for all supermarkets, and it is being used in several countries with significant political impact.

https://www.wired.com/story/heisse-preise-food-prices/