I'm planning on flying from Durban, South Africa to Victoria Falls, Zimbabwe next February. The trip can be had on a one-way basis using BA miles on Comair or BD miles on South African Airways for 10K in either program.

BD wants to charge me about 100 GBP in fuel and taxes for the one way trip - hardly worth it since the base fare is only about 60 GBP.

I have only 8,000 BA miles in my account but would buy the other 2,000 (or engineer a trade on CC) if BA's fees for a similar trip were more reasonable.

Since I am short of a redemption, however, BA.com won't let me see the final totals, advising me to return when I have the miles required.

Could a kind soul mock up a dummy DUR-JNB-VFA booking to the purchase page and advise me whether it's appreciably cheaper than an equivalent BA ticket?

Thanks in advance.