quoted price and asking price differs.

On Monday 14th December I was looking for flights from Cape Town to Johannesburg. On the British Airways Site I found an acceptable flight for R2844. I proceeded to the bookings page and the price was now R3211.12. I logged out of the site and retried. I got the same result 3 times.<br> I realise that on the quotation page there is a note saying that because of taxes the quoted price and the asking price may differ slightly. They offered an example differing by a few rand.<br> I do not understand how the price can differ by R278.12. <br> I also do not understand how all the other airlines including sister airline Kulula can actually charge the advertised price and BA cannot get it right. <br>