1. Envy

1. Envy

Have you ever considered buying a fancy new set of wheels or a bigger, better home to keep up with the Joneses? Envy can have a serious impact on your insurance premiums.

"When you're making emotional financial decisions, it's easy to forget about the underlying insurance costs," says Walker.

Remember, insuring a larger, more expensive home is likely to be a lot more costly than insuring a more humble abode.

"You need to ask yourself, what would it cost to rebuild my current home in its current location?" says Michael Barry, spokesperson for the Insurance Information Institute.

Trying to impress your friends by sprinkling expensive possessions throughout your home also carries a home insurance cost, Barry says. Walker agrees.

"Lifestyle envy will also result in more expensive 'stuff' that costs more to insure, along with pricey items — art, jewelry, antiques, electronics — that need extra insurance endorsements." says Walker.

And of course, don't forget how "automobile envy" can boost your costs.

"That sports car parked out front will be insured based in part on increased repair costs, so comprehensive and collision coverage will be more expensive," Walker says. "Liability costs may also go up depending on factors like crash safety ratings."

It's true that auto insurance rates tend to increase in line with surging horsepower. For example, the Porsche 911 Carrera GT2 coupe is among the most expensive cars to insure among 2010 models.  A 40-year-old man would typically pay a national average of $2,943 for car insurance annually, and that's assuming the driver had a good driving record.