This is my experience in Los Angeles as well. The Korean, Chinese, Armenian, and Mexican groceries are almost always cheaper than the national supermarket chain

This is my experience in Los Angeles as well. The Korean, Chinese, Armenian, and Mexican groceries are almost always cheaper than the national supermarket chains and often have better produce (with the exception of high end stores where you pay way more for quality) . NYC Chinatown may be a more extreme case due to density or something but American food marketing seems to have little to no effect on immigrant communities, which can easily support many low cost/high quality groceries in any metropolitan area.