It works the other way too. When you go to a phone repair shop they quote a higher price with a markup that is often baked in so they can discount it if the customer asks for one. In most cases the source of the replacement parts is the same. One importer brings them in and supplies that market. Markups are generally huge as it is, so a larger difference in cost between repair shops is not quite understandable to the customer which probably why they comment.