When Amy Hinkle of Palmerton shops for her family, she's not picking up small half-pound bags of shredded cheese or single portions of meat.

If you glance in her shopping cart, you'll notice a trend: Buying in bulk.Hinkle is part of a growing number of people shopping at a warehouse "club" store, and she prefers to shop at the Allentown Sam's Club once a month.It's helped the mother of five save significantly on her grocery bills since she started using club stores in 2007."My husband (Stephen Hinkle) likes to buy things in bulk," she said. "Anything that we can buy in bulk to save money, we do. Price matters."She previously shopped at BJ's, in addition to Sam's Club, to have access to higher quality items and organic meat and for a chance to use coupons (BJ's accepts manufacturer coupons, while Sam's Club does not), but has since dropped her BJ's membership."We buy all of our paper products there," said Hinkle of Sam's Club.With a large extended family and a love for entertaining, she noted that it's easier and less expensive to purchase paper plates, napkins, and toiletries in bulk.The family also stocks up each month on chicken, juice, peanut butter, snack foods, and canned goods such as tomato sauce and soup.Club warehouse stores typically have an annual membership fee. In the case of Sam's Club, you'll pay $45 each year to shop at their stores.BJ's charges $50 per year for membership. But club stores claim that the savings you'll find on their shelves help buyers quickly recoup their membership fee.Can you really save enough money shopping at club stores to justify the membership fee? A study done last year by Consumers' Checkbook found that shoppers could save nearly 30 percent by buying in bulk at warehouse stores.When Consumers' Checkbook compared the prices of three dozen grocery items from Walmart Supercenters to Sam's Club, prices were 18 percent lower at the club store. Sam's Club prices were also 22 percent lower than Redner's and 29 percent lower than Giant Food Stores.You would save 23 percent at Sam's Club as compared to ShopRite. or 13 percent if you're only looking at bulk buys at ShopRite.But what if you're already buying bulk items at a local grocery store? Consumers' Checkbook found that the savings aren't nearly as great.When you compare bulk prices between Walmart and Sam's Club, the club store is only 6 percent less expensive. Shopping at Sam's Club instead of Redner's, Giant Food Stores or Shop Rite, would save 9, 14 and 13 percent respectively.What Consumers' Checkbook doesn't compare is the cost of paper goods and larger purchases, which Hinkle estimates make up the bulk of their savings. They bought a grill at BJ's before their membership expired, and recently purchased patio furniture at a much lower price than the set they were considering at another store.She also buys some clothing through the store's website, which offers free shipping for members, and purchased diapers and wipes for their youngest children."We've more than made up our membership costs," she said.Hinkle agreed that the key to saving money at a warehouse store is to shop carefully. Stick to a list, and don't buy something you wouldn't normally purchase just because it's a good price.Patio furniture isn't a deal unless you were already shopping for furniture. Otherwise, it's just one more expense you hadn't planned on.If you wouldn't buy six smaller portions of animal crackers, Hinkle says you shouldn't buy the large tub of them at Sam's Club either.Buying in bulk: pros and consLike just about everything, buying in bulk has its pluses and minuses.Pros• Saving money• Fewer trips to the store• Convenience of having food and supplies on hand when you need themCons• Food that goes bad before it can be consumed• Membership fees• Lack of storage for dry goods• Need for additional freezer space• Additional cost for gas to travel farther• Spending more than a typical shopping trip, often resulting in putting purchases on a credit card, causing additional expense• Stocking up on snacks and then eating more than one might if they weren't in the houseInformation compiled from Business Insider and Investopedia