Why it's on the list: Fuel Costs; Depreciation CostsFirst up on our list is the Buick Regal. For a used car, it has one of the worst depreciation values on the list. If you ever decide to sell it, you won't get nearly what you paid for it. For a car that's only worth around $17,000 to $17,700, you're not looking at a whole lot back in your pocket when you look at the starting price for a new 2013 base model at $29,015. The other reason for the Regal being on the list is the price of fuel. Although it's not outrageous, you'll spend more money filling this car up than you would other cars in the same class. Not to mention, it’s a Buick.