To Buy or Not to Buy: Successfully shop at wholesale warehouses by being very careful. Some products are cheaper, such as dairy, some meat, baking goods, electronics, and a few big ticket items. The key is to compare price per unit with your local grocery and drugstores. Make sure you have room to store the bulk packages (usually an additional freezer and/or extra shelving is necessary for the avid warehouse-goer). To be effective, stick to a list, resist impulse buys, and price compare.
Impulse Buys: Carts big enough to sleep in tempt shoppers to impulse buy to fill it up. The problem is that at a regular store an impulse buy may cost you a few dollars, but an impulse buy at a warehouse can tack on $20 plus. Trying out a bulk new product that you end up not liking means a lot of space taken up by a leftover product that is never used and is even eventually tossed out. If you don't have a lot of mouths to feed, buying in big packages can be wasteful when things expire before you have a chance to use them.
Go Dutch: Love your local Costco, Sam's Club, or BJ's but can't stomach the whole membership cost? Consider splitting up wholesale bargains and club costs with a friend to take advantage of good prices on electronics, produce, dairy, eggs, and big ticket items.
Seasons and Cycles: Keep in mind that shopping sale cycles and weekly deals at more than one store with coupons (including great perks like Reward/Catalina promotions, stacking a manufacturer coupon with a store coupon, or price matching) can add up to much bigger savings than shopping a warehouse alone. National drugstore deals include free or moneymaker items, like oral care, medicine, household cleaners, and feminine products. Grocery store specials with coupons can get you pasta, cereal, soup, cake mix, boxed dinners, and more for under $0.50 each. Chain grocery stores also offer a wide variety of specialized food, a multitude of flavor options, and clearance items, most of which are usually not available at wholesale clubs.