Are Jaguars reliable cars?

I want to buy a Jaguar X- type 2007 6 cylinder for 18,000. It has 25,000 miles on it. Have any of you ever owned a jaguar or have one? Are they reliable cars? Do they get problems quickly? Are they expensive to repair? Does the X- type consume a lot of gas? Is it a comfortable car, and roomy? Is 18000 a good price to pay for this car?