Those solar stills are cheap enough, but slow, not portable, and they need good weather (sunlight) and lots of space. Moving water from a mile away isn't that big a problem, even without a working vehicle, given time and muscle power. I could roll a 13 gallon wastebasket full of water on a hand cart pretty easily, or jam a few 1 gallon bottles into a rolling suitcase, or even just carry one or two gallons.