(shifting from a comment to an answer)
Frameshift: this is quite possibly not necessary in the first place.
At least in big cities, you may very well be able to find stores catering to the diaspora.
If I google "bordeaux magasin indien alimentation" I find a number of "ethnic stores". They seem to be clustered together, near the center of town from the looks of it. Good opportunity to walk around, discover Bordeaux, and solve this differently.
Now, if it's anything like what I remember from living in Paris (and shopping at a Chinese supermarket in the 13th arrondissement). Or in Canada, where I live now, shopping at "ethnic stores", their prices are often much below "proper supermarkets".
So it pays to shop around, for general foods, and especially if you are looking for bulk and/or ethnic foods. Lots of people just care about getting good food without all the pomp and marketing costs that regular supermarkets saddle us with.
p.s. Not all such stores are cheaper. For example, where I live, Japanese specialty stores are often, not always, quite expensive and carry mostly high-end packaged branded goods from home. Mexican ones are often tiny and don't carry all that much. Sometimes you just have to visit to see if you are getting value or novelty-for-tourists.
But Chinese and Indian stores are usually better bets.
p.s. In any case, they feel a little bit like getting out of town which is why I like to shop in those places.
