Ignore all the nay-sayers and doom profits. If your monthly medical expenses is less than that of a medical "aid" (which only "aids" you to a certain point anyway and not beyond what you may actually need) then take what you would have paid on medical aid and pump that money into a savings account set out specifically JUST for that.
Get a cheapo hospital plan (Shouldn't be more than R800 AFAIK) or one of those "We will pay you R3000 a day you're in hospital for 180 days) type deals. That, combined with your accumulated savings should cover your medical expenses IF something nasty is to happen to you re: car accident or something serious.
If you're generally healthy and take care of yourself and don't take a lot of risks, then life insurance/hospital plan dealy with the savings account will be more than enough.
I was at a state hospital after my accident (nothing serious even though it looked very serious looking at the car) and the ambulance ride over was more expensive than that. Yes, you have to wait in line with other less fortunate people, and the doctors may or may not know WTF they're doing and the staff will give you a run around with files and tests and ****, but it's better than nothing and with the national health care plan (tax payers have to foot the bill for) it won't really be necessary in future. But anyway. I speak out of experience where my friend's baby had to have special care and he had to fork out R35k immediately which his R4k a month medical aid didn't want to pay out and he had to later claim it back from them. The interest on his credit cards were insane and yes, he got the money after 6-7 months, but "depleted" whatever his medical aid were offering and had absolutely no choice to fork out more money just to take care of his wife and child's medical expenses over and above the pre-natal care.