Costco has 3 ways to shop without a membership, but the math still favors paying the fee

• Costco has been clamping down shoppers using membership cards that don't belong to them.
• There are still ways to shop without a membership: online, with a gift card, or as a member's guest.
• The extra charges and hassle of workarounds can quickly add up to more than the annual fee, though.

Costco's Netflix-style crackdown on unauthorized membership sharing over the past year raises a perennial question about how to access the jumbo packs of toilet paper, tubs of peanut-butter pretzels, 40-pound bags of dog food, and other staples without signing up for a membership.