Also, I'm not sure who you've been talking to in SA, but neither of the helicopter schools I'm in contact with there recommend people do fixed wing before helicopter. You've probably found a school who do both, who would like to boost their income a bit.
When I looked at this, it didn't work out much cheaper to do fixed wing qualifications if what you really wanted was rotary. There was a very slight difference, but it relied on doing everything in absolute minimum hours, and added a lot of time before you were actually qualified. Most rotary employers don't seem to care about fixed wing hours (unless you have many thousands of them, and even then, it's not a major factor), so unless you have a specific use or desire for the fixed wing tickets, beyond as a stepping stone to rotary, it just doesn't make a lot of sense. YMMV, of course.