 Sensors can warn people to add oil that can prevent engine problems. Jeff Gilbert, CBS News, Detroit. Back to that earlier statement about dinosaurs. One of the most pristine stegosaurus skeletons ever discovered is up for auction. But you're going to have to dig deep for your favorite dino. The estimated price tag? Somewhere between $4 and $6 million. The auction takes place Wednesday at Sotheby's in New York City.