It's an interesting idea for a place like Australia - use solar power to desalinate water, and pump it inland. You could create an oasis in the middle of nowhere, sort of like Las Vegas.
You still have to deal with the bi-product of salt and other various minerals that come out of the desalinated water.
Genuine Aussie sea salt...
Most of them are of value? I mean, we buy salt, and esp. sea salt, and most of the other minerals are going to either salable, or at least disposable in some way. You'll even be getting very small amounts of stuff like gold too. (really not much at all, but hey, there's 20 million tons of gold in there)