For US$150 (one-way) you can fly from Cochabamba to Uyuni. It's not cheap but if you can afford it, it's worth it. When will you ever ride DC-3, an old propellor-driven plane, with a pilot in his leather jacket and all? Of course, you can become ill from high altitude. But don't worry. The nice flight attendant will bring out a huge tank of oxygen, just for you. =) (see the photo) This option is recommended for anyone with limited time in Bolivia.