Here's a 2 bedroomed apartment in the Cape Town CBD on sale for R1 400 000 (hat tip to reader AS for the link), with a current rental income of R6 000/month. This sale is listed as "urgent" but when you consider the terrible rental yields you can expect I don't think they quite mean it. Here's the payment and yield graph:
So with a 100% bond the difference between rental and bond payment is R-12435, over twice the rental itself. You only break even on cash flow if you put down over 2/3 depost (R944 346) and even with a 50% deposit you still need 2.76% capital appreciation to not lose any money. And this is with the gross rental, deduct maintenance, rates, levies and vacancy costs and the numbers get worse.