Thanks for the details. And your last line........trip planning is half the fun.
I'm from India and will need visa for both Chile and Bolivia.So I want to restrict my travel to one country Bolivia.
Or should I go for Chile if I have to choose one?
I'm planning to fly to Salta from BsAs and then take bus to Salar de Uyuni Bolivia, spent 3 days in Salar and return by same route. Can you please give more details on Salar - details about Salar Salta journey and trip you did in salar?
I will try to advise you well but I'm a little bit confused by what you are asking.
I went to Uyuni from San Pedro de Atacama Chile, and then back to Chile before I crossed over to Salta, Argentina on the bus. If you are going from Salta to Uyuni, you take a bus to La Quiaca (border town where you cross to Villazon, Bolivia), and then you can take a train from Villazon to Uyuni!
If I had to choose between Chile and Bolivia, I would choose Bolivia because it is half the price and equally, if not more, beautiful. There are some unique things in Chile but I found that all of the activities/tours I did in the north of Chile around Atacama desert, there were similar things (beautiful and bizarre landscapes, geysers, lagoons - although different looking but you see so many lagoons it can get tiring) but Bolivia is just SO MUCH CHEAPER. But the locals are not as friendly and the chance of getting robbed is slightly higher than in Chile; I only speak from personal experience as I was robbed in Bolivia (in La Paz) but never in Chile, north south nor center. But if I had to choose out of the two, it would be Bolivia.
The Salar de Uyuni is one of the coolest places you will ever see. Nothing in Chile can compare to that level of amazing. But I will try to explain this well... all the tours from Uyuni are either 1 night or 2/3 nights. The 1 night tour (or even just a day tour is possible? I don't know) only go to the SALAR- the salt flats. Hopefully if it's not wet season you can go to the island full of cacti in the middle of the salar. I didn't get to go because it was end of wet season and too dangerous to drive on water. If you get the tour that is 2 nights or more, then you will go south of the salar also to see the many lagoons and the "rock tree" and the hot springs which are all at much higher elevation. Then you spend pretty much an entire day (or 2 days!) driving all the way back to Uyuni.
On the tour I did from San Pedro to Uyuni, we stopped in those southern places first, and ended at the salt flats. Actually it was great this way because we stayed in the town of Uyuni on the last , and then we got to go to the salar (which is just outside of town less than 1 hour drive) for SUNRISE!!! This was the best. I know that a lot of the tours that leave from Uyuni which go to the Salar first, they start in the middle of the day and you don't get to see the sunrise. So if you are going from Uyuni on a salt flat tour, see if you can do one where you get to go at sunrise. It's unforgettable!!