minimums....
Yrs Exp vs Salary
3-5+ - R20k/m (subtract 1 with bachelors, 2 with honors, 3 with masters)
05+ - R28k/m
10+ - R40k/m
20+ - R60k/m
30+ - R80k/m
darn got a long way to go

though I think a better way of looking at it is by substituting yrs exp or studies as I've done to the above quote. If that's done I'm still on target.
Why do that? It makes more sense. Looking at the table now it looks right but the funny thing is the start point. Some industries start really crappy and the only way to double up fast is to job hop which I think is where some cities have it tough. Cpt for example has notoriously bad salaries for starting.
Another observation give the above table is that after 20+ yrs if you really want to make salary double up fast, pending industry, you may need to do something drastic. Eg. Go into private business (medicine), start your own business, rental income, franchise, move into management (MBA) etc otherwise it will plateau.
If you want to jump faster up from earlier, ie after the 10yr mark same thing applies. What's interesting I find is that some will have it easy up front but plateau fast while others will have it tougher upfront.. But either way, to get somewhere fast drastic action is needed at least 1-2 times in career.
PS. People who really make it salary wise don't rely on salaries for anything but having security while pursuing other business I've found. ie. they have other business which usually earn them the same to 3x as much which seems improbable but is not at all. I think the whole salaries will make you enough money syndrome in SA is something most people have thus don't understand how people earn far greater than 1mil