Both Sam's Club and Costco wholesale stores say they offer up to 30-percent discounts on brand items. So why don't you always see those savings? Consumer Reports says, for one, people buy way more than they plan to get.
Consumer Reports' Tod Marks says maximizing the savings takes some discipline.
"Before heading out to a warehouse club, make a list and then stick to it," said Marks.
That means resist the urge to browse. You can get great deals on electronics and jewelry, but is that what you headed in to buy? If you're short on willpower, Consumer Reports says to try shopping at the club websites.
"Sam's Club has this great service called 'Click 'n' Pull.' If you place your order online before 5 o'clock, you can pick it up the next day," said Marks.
And both sites offer "online-only" specials. Back in the stores, check out unit prices. That way you're sure you're paying less than you would at the grocery store. Sometimes you're not. And if the big packages are too big, good news: The warehouse clubs are offering some smaller sizes in a lot of staples.
"But some items still come in bulk. So if your favorite products are only available in bulk, consider splitting it with a friend," said Marks.
Another money-saving move: try the cheaper warehouse club brands, like Kirkland Signature at Costco and Members Mark at Sam's Club. Many products have rated highly in Consumer Reports tests.
Membership at Costco starts at $50 a year, Sam's Club at $35. If you're not sure it's worth it, Sam's Club offers a one-day pass that allows you to buy anything you want with a 10-percent surcharge.