I would say either get an old car for QR20,000 or less or a brand new car. As e46 said, you can only get 3rd party insurance on an old car so if you are in an accident and the police say it is your fault, you have no insurance cover for your car. Usually, it is only possible to get comprehensive cover for the first three years of a car's life. So if you want comp cover get a new car.

had better live as we think, otherwise we shall end up by thinking as we lived. - Paul Bourget