Is the electricity price in the South Africa cheap? If so, they can buy miners from China and mine there.
Bitcoin price in SA is also getting fueled by MMM and other get rich quick ponzi schemes, not only the USD to ZAR price difference. The electricity in South Africa is sketchy during winter when everyone uses more heaters, kettles and stoves etc., so we have 'load shedding', where certain areas of the country have no power at all for an hour or two every day. It's also hot, so cooling effectively costs more money, so its not really profitable. Ordering mining equipment online also takes ages to get here since the postal system is so bad, and if you use a courier company, the cost needs to be factored into the price...and its really expensive to send equipment here.
At the moment I am not mining at all because its just not profitable enough, and the risk of not breaking even is too high. Its far more profitable to do arbitrage between exchanges like www.bitx.co.za and www.ice3x.com.