I think at today's exchange rates Korea is closing the gap in many categories (a few highlighted.) Of course Korea also offers a 3-continent option.
Code:
South Africa
4 continent ZAR/USD 0.09998 USD ex-USA Diff
Economy ZAR 19,700 1,970 4,400 (2,430)
Business ZAR 45,000 4,499 9,100 (4,601)
First ZAR 66,500 6,649 12,500 (5,851)
5 continent
Economy ZAR 22,700 2,270 5,100 (2,830)
Business ZAR 51,500 5,149 10,400 (5,251)
First ZAR 76,500 7,648 14,400 (6,752)
6 continent
Economy ZAR 26,600 2,659 6,000 (3,341)
Business ZAR 60,500 6,049 12,000 (5,951)
First ZAR 90,000 8,998 16,900 (7,902)
Korea
3 continent KRW/USD 0.0006872 USD ex-USA Diff
Economy KRW 2,905,500 1,997 3,900 (1,903)
Business KRW 5,686,200 3,908 8,600 (4,692)
First KRW 8,881,400 6,103 11,600 (5,497)
4 continent
Economy KRW 3,486,700 2,396 4,400 (2,004)
Business KRW 6,776,800 4,657 9,100 (4,443)
First KRW 10,098,900 6,940 12,500 (5,560)
5 continent
Economy KRW 4,009,700 2,755 5,100 (2,345)
Business KRW 7,789,600 5,353 10,400 (5,047)
First KRW 11,604,600 7,975 14,400 (6,425)
6 continent
Economy KRW 4,611,200 3,169 6,000 (2,831)
Business KRW 8,787,400 6,039 12,000 (5,961)
First KRW 13,345,300 9,171 16,900 (7,729)