By Reyna Gobel
MoneyMix Contributor

How do you know if you're paying too much for items you buy on a regular basis? Check the real-life markup.

When you hear about markups on products, generally it's the cost difference between what the business pays to produce and sell the product and the sales price. Unless you have a direct connection to a wholesaler, you'll rarely buy an item at a retailer's cost, but you still can find ways to save by learning and comparing real-life markups on everyday products.

food markups

Are you paying too much for groceries, even when you stock up on your favorite cereal for 50 cents less than its normal price? According to Teri Gault, founder of The Grocery Game, Santa Clarita, Calif., you are. "Most grocery items are marked up double or more," says Gault. To cut your grocery bill in half, stock up on everything but beverages and produce during half-off sales. Combining coupons with sales yields an average savings of two-thirds off regular prices.

How else can you save on groceries? Gault offers these tips:

• Buy cases of bottled water from the grocery store instead of singles. A bottle of water in a case of 24 averages less than 18 cents during a typical sale. Convenience stores and gas stations typically sell singles for $1.12 or more—at least a 700% markup.

• Achieve larger savings by forgoing bottled water and drinking tap water. A glass of tap water adds a penny or so to your water bill.

• To cut your grocery bill in half, stock up on everything but beverages and produce during half-off sales.Buy ground coffee or beans from your favorite coffeehouse. You'll get the same taste homebrewed. For instance, a one-pound bag of Starbucks coffee typically goes on sale for $7.99 at supermarkets. That bag will make at least 27 tall coffees. That's 30 cents a cup vs. around $1.90 in a store.

• Pack your own lunch. This usually costs about $1 to $2 a day, or 10% of the cost of dining out. If you don't have time to prepare lunch in the morning, you can set it up the night before. Or, if your workplace has a frig and microwave, buy high-end frozen meals for $3 on sale or $2 with an accompanying coupon.

• Wait for breakfast cereal sales. Sales and coupons for 70% to 80% off regular prices are routine. Never buy a breakfast cereal when it's not on sale.

beverage markups

Cold coffee and hot bottled water isn't very appealing. However, with markups of 600% on a cup of coffee and at least 700% on bottled water, Gault recommends a small equipment investment in temperature-control products and home-brewing equipment:

• Insulated water bottles. For tap water on the go, buy an insulated bottle to keep your water cold for hours. Your $15 to $25 investment will pay for itself in 14 to 22 forgone convenience store bottled water purchases.

• Coffeemakers. For around $30, you can buy a basic coffeemaker and a reusable filter. Throw in a $15 coffee bean grinder, and you'll pay for your new setup with your savings from brewing at home before you use up your first pound of beans. Finally, buy an insulated coffee mug or thermos for as little as $15 to take your homebrewed coffee to work. It will only take nine 12-ounce cups for your investment to pay for itself.

loyalty programs

Many stores offer coupons to loyal customers through e-mail subscriptions, grocery store loyalty cards, or punch cards at sandwich shops. But when you use a 25%-off coupon, the store's markup assures that it isn't losing money on this transaction, says Dr. Malcolm Getz, associate professor of economics at Vanderbilt University, Nashville, Tenn. For instance, if you buy a $50 shirt for $37.50 with a coupon, the store still makes money off the lower price. If you get coupons on a regular basis, you're overpaying if you don't wait for the next coupon.

customer experience value

"Price is only one part of a store," says Getz. "Savvy shoppers look for good prices, convenient locations, and the level of service that meets their needs, but face trade-offs."

For example, depending on your shopping skills, selecting the perfect outfit for a job interview or career-changing meeting can take days of searching. But in a store with staff on par with personal stylists, days of shopping are reduced to hours. Of course, there's a markup for exceptional customer service: Retailers pay more money to hire experienced sales staff.

Sometimes, a 700% markup on bottled water when you're thirsty and don't have an insulated bottle in tow is worth it. And sometimes you want to sit with friends at your neighborhood coffeehouse with a croissant and coffee made just for you. The trick is to get your money's worth. Treating yourself occasionally is that much sweeter when you're finding ways to save money the rest of the time.