Wasn't sure what you were aware of. Newegg doesn't even ship to Canada, but I believe they do ship to military personnel. If you did happen to know some US military guys, that'd be a loophole, but I don't even think we have any troops in SA.
I don't know if you've Googled it, but I ran a search for South African computer shops and came up with
this. I don't know how it compares with local stuff, but if they're like a lot of online shops in the US, it's probably a bit cheaper than the local shops.
I started to look around, and I found that
TigerDirect does ship internationally. They're not my first choice, as they've had some issues in the past, but still might be worth a shot.
Another one I found, and have never dealt with before is
ExcaliberPC.
(Yes, I know I've linked to the FAQ's.)