I can only speak for those that have degrees, from a university (which I highly recommend). If you don't have one the rules may only apply after you have significantly more experience.
What you get paid on your first job is more a reflection on the company than on you most of the time.
Most companies don't know how to assess skills, so they hire you with a pretty shoddy interview. That is usually how they hire "experienced" developers also, btw. They just rely on the "experience" of the developer as a selling point.
The more mature a company's hiring process the higher the salary. The reason is simple, few people make it through the interviews. Hiring a developer is super expensive. And most importantly attrition can cost a company up to year in salary of whomever is replacing the person that left.
That said if you aren't working in Pretoria, Johannesburg, Cape Town or Durban your salary prospects will quickly dwindle.
As your first job, you should aim for the sky really. People seem to think you need to work your way into a good company. It is the other way around. Good companies are easier to get into as a junior. You are more likely to make it into Google.com, Facebook.com, Amazon.com as a developer with no experience than a developer with years of experience. The reason is you are going to be compared against your peers. SA doesn't really have much to offer in terms of experienced developers. It isn't the people it is the local environment. We don't have the same innovation opportunities here and that means a good developer never makes it further than just being a good developer.
If we are talking strictly money tho. My current company pays around R30k p/m to a straight out of university graduate.
My first job paid R20k p/m in Pretoria. All my friends from University of Pretoria earned R20k p/m or more for their first jobs. That was about 4 years ago.
Currently I would say the new standard should be about R25k p/m for a company that has a fairy decent name and a good interview process (skills assessment, not this hippy BS about your feelings HR usually makes you take).