There's an absurd JNB-LHR-INV r/t for £885 in J (787, 747, 380 options) pretty much year round. You can use 140,000 Avios to reduce the price to £208 equivalent. Pretty tidy considering the 360TPs and 31,700 Avios (as GCH). Very, very tempting - but positioning is tough for me so not sure I can make it all work.