2000-4000 dollars. This is very average though. It would depend on if you are buying it used or new. Other things it would depend is condition, brand, seller, and the parts they put into it. I would say if you are buying a quality dirt bike new it would cost anywhere between 2,000-14,000 dollars. Used would probably be anywhere from 500-9,000 dollars. There are more expensive ones but this is for a quality dirt bike, not an extremely professional dirt bike. Caelan Aurilio.