Second that. Your tickets are going to cost a fortune and there's just no way around it. When I was based in Lagos, I twice had to fly to CDG in order to connect back down to Yaounde and Luanda. The problem was more scheduling and reliability than cost of the ticket as price wasn't an issue, but even so, the Africa-Europe-Africa thing isn't all that strange.
Can I recommend though that you look into redeeming miles on KQ for your intra-africa flights? KQ takes NW/KL/AF miles, maybe even the other skyteam members too, and their intra-africa award is cheap at 25k roundtrip, with one free stopover. open jaws are allowed. I used two awards in recent years: LOS-NBO stopover NBO-CPT stopover JNB-NBO-LOS and then LOS-NBO-JNB vacation JNB-NBO-LOS. Considering that the tickets i used miles for could have easily cost $1500 or more, 25k miles is a great value.