Yeah. I live in a small suburb outside of PE. You may not be aware of it but there is finally light at the end of our eight+ year drought so we're pretty well versed on water issues.
It falls free from the sky. I'd call that pretty cheap. All you need is a roof, some gutters, and something to store it in. I myself currently have 12Kl of harvested rain water and have relied on it completely for roughly 40% of the last two years and partially for the other 60%.
I've sent a lot of time in the third world, outside of SA. Some of it helping to promote availability in remote areas of Uganda and some documenting issues in the slums of Nairobi.
In some areas it's quite an equitable system, in others it isn't. A lot of depends on topography and distribution.
Indeed. Even SA