Sure, it looks great in the showroom. And you figured out you can afford the payments. But how much cash will it cost over the long haul?

Required expenses such as gas and insurance can make a big difference after you take your four-wheeled baby home. Depreciation, a measure of how well the car does or doesn't hold its value, could cost you thousands at trade-in time.

Analysts at Edmunds.com calculated the cost of ownership for a slate of 2007 models. The formula factors in the average sales price and financing rates, plus the cost of typical ownership for five years, taking into account gas mileage, insurance, taxes, maintenance, repairs and depreciation.

10 least expensive 2007 cars to own

Vehicle Cost to own   (for 5 years) 1. Chevrolet Aveo $29,362 2. Honda Fit $29,914 3. Honda Civic $30,107 4. Toyota Yaris $30,257 5. Hyundai Accent $30,386 6. Nissan Versa $30,791 7. Kia Rio $30,984 8. Toyota Corolla $31,269 9. Mazda 3 $32,100 10. Jeep Patriot $32,544

Source: Courtesy of Edmunds.com, 2007

The least expensive vehicle to drive? Chevrolet's Aveo, with a five-year ownership price tag of $29,362. "It's so inexpensive, it's close to being the cheapest car you can buy," says Philip Reed, consumer advice editor of Edmunds.com. "And the related expenses are also fairly low."

The Honda Fit came in second, costing $552 more than the Chevy over five years. But it was a different set of criteria that put the Fit on the list, says Reed. "The purchase price was a little higher, but the depreciation was so low," he says.

On the other end of the spectrum, the most expensive to own was the two-door Mercedes SL-Class, with a five-year tab of $220,671, according to the analysts. "The primary cost associated with the over five years is depreciation," says Alex Rosten, industry analyst for Edmunds.com's Auto Observer. And a price tag of $95,000 to $187,000 new is a big factor, too, he says.

Another Mercedes-Benz, the four-door S-Class, came in second with a five-year ownership cost of $215,593. Same reasons, says Rosten. The cost ranges from $85,000 to $181,000 new, "and there isn't that much of a market for $80,000 or $90,000 used luxury vehicles," he says.

What makes a car pricey?
A lot of factors determine whether a car is expensive or inexpensive to own.

Depreciation is a huge part of the "true cost" of ownership. If you plan to sell it, says Rosten, you need to look at what the car will be worth five years from now.