5 Things You're Overspending On

In these cases, spending lavishly won’t necessarily give you the best value for your money.

Tips on getting to “I do” and beyond
By + More

But many consumers don't understand how to finance a car properly – or they understand, but due to financial pressures, go ahead and get the car anyway, hoping for the best.

Helpful to keep in mind: Interest.com, a financial website, issued a car affordability study earlier this year and concluded that of the nation's 25 largest cities, consumers in only one – Washington, D.C.– could actually afford to spend $30,000, the average cost of a new car or truck. Everyone else, as a group, is buying cars they can't afford.

So how should you pay for a car, new or used? If you don't want to get in over your head and pay excessive interest, Interest.com suggests making a 20 percent down payment, financing the car for no more than four years and making sure the principal, interest and insurance don't exceed 10 percent of your household's gross income.

"You also have to keep the insurance price in mind," Francis says. "Insurance premiums increase with the value of a vehicle. The more expensive the vehicle is, the higher the annual insurance costs."

Mattresses

Why it's easy to overspend: Although there are people who claim to be able to get by on four hours of sleep a night, most people spend roughly a third of their lives asleep in bed. Sleep is important. Comfort is, too. There are a dozen arguments for opening up your wallet and buying the most expensive mattress out there.

[See: 10 Ways to Cut Your Spending This Week.]

Helpful to keep in mind: Not that you should necessarily buy the cheapest mattress out there, but listen to your body and not the hype.

In the May 2013 issue of Consumer Reports, the magazine tested 12 mattresses, and the mattress that earned the highest ranking, the Beautyrest Glover Park Firm Pillowtop, retailed for $780, while the ComforPedic Loft Crestwood Luxury Plush mattress, which cost $1,200, ranked lowest on the list.

"Instead of getting the most expensive mattress, try it out and see how it makes you feel," says Mudit Sharma, a neurosurgeon at Spotsylvania Regional Medical Center in Fredericksburg, Va. "A medium-firm mattress tends to be the most comfortable for the majority of folks."

And if it so happens that the mattress you've been testing and enjoying is one of the cheaper ones, then, no, you're not dreaming – buying it is a good decision.

Corrected on 10/10/2013: A previous version of this story misstated the name of the company CEB TowerGroup.