Is it worth buying a mining rig now? I'm still building more of them, so for me the answer is yes. Your answer may be different.
1) Do you believe in the big-picture idea of cryptocurrency? If yes, maybe. If no, probably not.
2) Are you financially able to withstand the build out costs, maintenance costs (shit breaks), and electrical costs without taking immediate profits? If yes, maybe. If no, probably not.
3) Time: Do you enjoy tinkering with computers? And by "tinkering" I really mean regularly diagnosing why _insert_something_here_ suddenly stopped working? If yes, maybe. If no, probably not.
Finally, assuming you made it this far having answered yes to the above: 4) Is it for some reason (be it personal, professional, or regulatory/whatever) more convenient for you to mine coins rather than start dollar cost averaging in by just buying the coins directly? If yes, then absolutely. If no, then...maybe.
This made mining look quite sophisticated. Maybe it explains why it's hardly obtainable is western parts of the African continent except South Africa. The demerits outweighs the merits for folks in that region