You should be clear on what you want to pay, the Chinas sell them from R1000 and up. And if you want a reputable brand you will pay from R2500 and up. Paying R5000 is not unexpected.
I must say for a "nany cam" that normally means dirt cheap quality, you will be happy with the R1000 china cams. You can have a look at any china mall, like Pretoria North has a "market" on Zambezi drive. Centurion has a "oriental plaza" on Old Jhb Road, and Joburg has the very big "China Mall" near Gold Reef City.
The R1k Wifi IP Cam from the chinas has TPZ controls that you can control from a cellphone app. It is only the video that will be very grainy. And it has night vision, but only useful if the subject is close to the cam.
You didn't mention if you want to the cam too be "stealth". Like quiet or "hidable". This is not that popular unless you visit a big Baby shop, like Baby Boom. But the chinas do sell a few very small "Spy Cams" or hidden offline cams that you can review afterwards for cheap (they don't have build in wifi or 3g).
You can also go look on DX.com (DealExtreme). They sell all the same china cams for cheap, you just need to expect a heavy delay on the delivery.