As was mentioned, start-up fares are start-up fares. I recall when VS got the JNB route and there was the usual fan fare of lower prices.
Not for long!!! I've been travelling this route for nearly 48 years and over the 16 years that I used VS (and others) on this route, their prices have always been roughly aligned. There are - of course - variations but when you look at the peak times and the details?
It's called business and NAS are very good at it!