Tk lax/ord - jnb - $905 usd (~4 cpm)
Came across another one for months of January and February:
From LAX - JNB :
https://www.google.com/flights/#sear...=STAR_ALLIANCE
From ORD - JNB :
https://www.google.com/flights/#sear...=STAR_ALLIANCE
LAX - JNB nets about 23,000 miles for the roundtrip and ORD - JNB nets about 20,000 miles for the round trip.