Does AF fly to CPT? I thought AF flew to JNB and KLM to CPT? If so, you might find that your LHR-CDG-CPT is actually LHR-CDG-AMS-CPT and its a day flight from AMS which is not great, arriving very late at night, which is even worse and on really cr*p business seats! It depends what you class as value for money but I think I would spend my ££ on another route and product.