It depends on the length of your tour and also from which town you start. If starting and ending your tour in Uyuni, Bolivia, three-day tours (the best option if you want to see the key highlights of the Salar de Uyuni) cost from $180 USD pp for a group tour.  Alternatively, you can start in Tupiza, a town three hours south of Uyuni. Tours from here tend to be four days and three nights and cost from $195 USD pp for a group tour. The extra day is well worth it for the remote scenery you get to explore, as well as the fact you arrive at the salt flats at sunrise - before all the tours from Uyuni! The final option is to take a tour of the salt flats from San Pedro de Atacama, a town across the border in Chile’s Atacama Desert. These tours tend to take three or four days (depending on whether you want to return to San Pedro de Atacama or continue to Uyuni) and cost from $190 USD.  Private tours starting from each of the above destinations are also available. You can expect to pay a lot more, as you’re paying for an entire car, rather than a seat in one; prices start from $1,500 USD per group.