There are only three different options for sleeping inside the National Park: camping (free and paid), refugios (trail huts) or in a hosterĂa (upscale lodge). There is NO pirate camping, meaning you may only camp at the designated campsites.
There are two different types of campsites in the park, paid and unpaid. If there is an open and working refugio next to your campsite, then you will have to pay up to 4.000clp ($8 usd) per person, not per tent. For this fee you receive all campsite and backpacker services that the refugios offers, which include water, bathrooms, mini-store, cooking areas and the option to buy a hot meal. You do not need a reservation for a camping spot anywhere in the park. If there is NO refugio next to your campsite, or if the refugio is closed, then camping is free. But there are no services. You must be completely 100% self sufficient to camp at these sites. There is always a creek near by for water and an outhouse or drop toilet for campers to use. There are NO garbage services at the free campsites, but you can dump your trash at the refugios. On the back circuit there are no free campsites, and not always a refugio. Free campsites include: Los Guardes, Italiano, BritĂ¡nico, Japones, Las Torres, Paso, Pingo, and Las Carretas.
Refugios can be found in various locations on the trail within Torres del Paine National Park. Refugios are private and independently managed. Refugios offer dorm beds (roughly $40 usd), basic hot meals (roughly 18 usd) and paid campsites (roughly $8 usd per person). Meals can be purchased on the spot, but beds should be reserved in advance to guarantee availability. Normally you need your own sleeping bag, but some refugios offer upgrade options. Booking in advance is a very good idea. Contact Fantastico Sur (firstname.lastname@example.org ph+56-61 360361) or Vertice (email@example.com ph+56-61 412742). Refugio reservations can also be made at info(at) erraticrock.com.
The hosterĂas in the National Park are the more luxurious option for sleeping close to the trail head. Most resemble rustic lodges and have everything you would expect for the price range. Some are located directly on the main trail of the 'W', others are located the perimeter if the park boundries.