Answer: The one-stop shopping these businesses provide is extraordinarily convenient, and prices are consistently low.
Step-by-step explanation:
This sentence lists two advantages to shopping at national chain stores such as Walmart and Costco.
The advantages are that prices are lower and they offer convenience thereby saving people time on shopping because the wide array of goods they offer means that people can get most if not all that they need from these shops without having to hop from shop to shop to find different items.