I have a Chevy Equinox that needs new spark plugs. Where would be the place to buy the best quality spark plugs for a low price?

Call up your local parts stores and see if they sell the proper AC Delco plugs for your vehicle. Some deals can be made by going online and ordering that way by entering a coupon code, especially with Advanced Auto. Online parts ordering is usually even cheaper if you don't mind waiting a few days to get them. Start with Rock Auto as I'll bet they'll have decent pricing.