Well, I definitely paid for an upgrade on an SAA flight from Munich to Johannesburg and the price was EUR1,000. I paid for the upgrade at Munich airport, at the ticketing desk by the gate past security.
Can anyone shed any light on this seeming discrepancy? One factor might have been that my original flight ticket was booked on Swiss (economy class) though we were placed on an SAA flight because our Swiss flight was cancelled due to weather.