Very cool! I did something similar in Canada (https://grocerytracker.ca/)
I did the same and made https://grocerygoose.ca/
Published the API endpoints that I “discovered” to make the app https://github.com/snacsnoc/grocery-app (see HACKING.md)
It’s an unfortunate state of affairs when devs like us have to go to such great lengths to track the price of a commodity (food).
A thorny problem in my case is that the same item is named in 3 different ways between the 3 supermarkets which makes it very hard and annoying to do a proper comparison.
Did you have a similar problem?
I have the additional problem that I want to compare products across France and Belgium (Dutch-speaking side) so there is no hope at all to group products automatically. My manual system allows me to put together say 250g and 500g packaging of the same butter, or of two of the butters that I like to buy, so I can always see easily which one I should get (it's often the 250g that's cheaper by weight these days).
Also the 42000 or so different packagings for Head and Shoulders shampoo. 250ml, 270ml, 285ml, 480ml, 500ml (285ml is usually cheapest). I'm pretty sure they do it on purpose so each store doesn't have to match price with the others because it's a "different product".
I am thinking of doing the same thing for linux packages in debian and fedora
My approach so far has been to first extract the brand names (which are also not written the same way for some fcking reason!), update the strings, and then compare the remaining.
If they have a high similarity (e.g. >95%) then they could be automatically merged, and then anything between 75%-95% can be reviewed manually.
Granted it was around January, and things may have progressed...
(Βut then again why take the easy approach when Ι can waste a few afternoons playing around with string comparisons)