Who should join
Join when Costco supports the way you already spend
Membership is strongest when it reduces friction across multiple categories you actually use, not when it is expected to rescue a weak shopping plan.
Families, couples managing a steady home budget, and shoppers who already know they will buy both staples and at least one larger item each year tend to get the clearest value. The membership can also make sense for business owners whose supply basket overlaps with household shopping.