I'm not sure about US dollar stores but there are really good deals at Japan's 100 yen shops. For example simple plastic boxes that cost 10 euros in France are

I'm not sure about US dollar stores but there are really good deals at Japan's 100 yen shops. For example simple plastic boxes that cost 10 euros in France are at 100 yen in those shops. So in Japan it's not just for poor people, there are items where it doesn't make sense to buy them anywhere else than a 100 yen shop.