In Toronto, I buy about half my food at large independent Asian supermarkets. My favourite, BestWin, is awesome/cheap for meat, and cheap for almost everything else (produce, rice, bread, legumes, atta). There are also a lot of entertaining snack foods, but they're as fake and fatty as anywhere else.
I concur with other posters in a couple of respects:
*Such stores are not great for non-Asian stuff. Buy your muffins and tortillas elsewhere.
*The produce has a shorter shelf life. The owners are almost certainly buying marked-down stuff at wholesalers. They expect customers to know how to deal with produce problems, i.e., don't keep those dodgy red peppers in the fridge for a week.
To optimize shopping at these places:
*Buy staples in large sizes. Maybe repackage them in bins. And consider adjusting your dinner menus for the month to get through them.
*Deal with produce quickly. Either use it up fast, or treat it to last longer. For red peppers, for example, which are WAY cheaper in these stores, I roast and peel them the day I buy them, then refrigerate or freeze them. Or use them to make a huge batch of sambal or salsa. My next step is to start making (separate) purees of ginger, garlic, cooked onions, and peppers, to keep in the freezer for really fast Indian meals.