It’s a familiar struggle.

In one hand, there is a 16-ounce bottle of ketchup; in the other hand, a 64-ounce bottle. The division rules and multiplication tables are rolling through your head as you try and figure out just which bottle is the best buy in the long run.

According to The Simple Dollar, a personal financing blow, it’s simple math that wins every time.

Buying in bulk gives consumers the single best benefit in an economic downturn: less money for more goods.

“This is the biggest benefit of buying in bulk, and it overshadows everything else. Almost always, when you buy in bulk, you’re saving money per unit, which adds up to a real savings over time,” Trent Hamm, creator of The Simple Dollar, wrote online.

Some bulk merchandise providers, such as Sam’s Club, want to help consumers save more when buying in bulk.

“We have a few ways to help our members save by purchasing in bulk,” Kristy L. Reed, manager of corporate communications for Sam’s Club Public Relations wrote in an email to the Suffolk News-Herald. “Recently, we developed a Web site to help families create ‘Cooking Clubs.’ For this, three friends get together and make food for their families for a week. We have developed recipes, shopping lists, etc., to help our members.”

But consumers should keep a few things in mind before going on a bulk-buying frenzy.

For starters, not every bulk buy is a bulk saver.

Some items are simply more expensive because they come in a larger size or greater volume. Hamm recommended shoppers view the price-per-unit sticker, which is available on most items, before making a purchase.

Secondly, shoppers need to think practically.

Many bulk items are larger and therefore take up more space in shelves, pantries and refrigerators.

“When buying in bulk, your ability to store the product is a key consideration,” Arthur Cooper wrote in his article “Benefits of Buying Bulk” for ArticleBliss.com. “Don’t buy more than you have space to store properly.”

Additionally, Cooper reminded shoppers to think about the amount of food they purchase, because it will have to be properly stored to keep from losing the food altogether.

“Remember that everything we buy is perishable in some way,” Cooper wrote. “Food products expire or lose quality, and paper goods can be damaged by dampness. Make sure that the products you are planning to buy in bulk are things you will be able to use up before they go bad or degrade. If food spoils or is infested with pests, you will have to discard it, and buying food in bulk may end up costing you more.”

Finally, Cooper suggests that the best buying bulk tip is to buy the things that are usually bought singly, such as toilet paper, paper towels, cleaning supplies, sugar, flour and grains.

“Stored correctly, anything that you use regularly or use a lot of can be purchased in bulk and save your family time in replacing those goods — and money,” Cooper wrote.

For more information on Sam’s Club’s Cooking Clubs program, visit http://www.samsclubmemberservices.com/cooking-club.aspx.