From personal experience. I am willing to assign a higher value to products made by local and/or small businesses, even if it doesn’t otherwise make any practical sense. But it is a very conscientious moral judgement on my end, so I don’t expect most people to behave this way… and I have a limit too, +100% is probably too much.

Although I guess the benefit of being a “small” business is that you also don’t need as many customers… There are also some types of small businesses that are competitive: I suppose most ethnic food stores or your local market stall won’t struggle with competing on price.

how is it that there are any little shops left at all?

Maybe this depends on the area? I don’t know if it is just me, but it seems to me that these days small businesses do better in larger cities… maybe larger cities have more “ethical shoppers”