Price is probably more important than location to most buyers. You can pay too much in affluent Waterkloof or Clifton, just as you can pay too much in Pretoria Noord and Milnerton.
Bargains can be found in less expensive suburbs as well as in expensive suburbs but generally you will exjoy the maximum capital growth bu buying the cheapest stand in the most expensive suburb.
Properties will always have a North (hot) and a South (Cold) side, whether you are on the North-side or South-side of a hill-side. South entry, North Facing stands are the most popular for residential buildings.
Buildings constructed on clay, sand or rock can add as much as 5% to the total building costs. Expect to pay 3 . 4 times the stand price for your finished building for a balanced investment ratio.