"The more expensive the car, the more important the service records are," says Sarcona. You should beware of sellers who aren't forthcoming with maintenance histories. Cars that look and run well can have very expensive maintenance costs just around the corner. For example, you can score a Ferrari for less than $30,000, but it might be on the cusp of needing a $5,000 timing belt replacement since these vehicles require a new one every 7,000 miles or four years.