I'm looking at buying DONE4 ticket. It appears the cheapest place that is easy to get to is either Cairo or Istanbul. The price seems to be about the same either place. What about taxes? It seems lots of people start in Cairo but few in ex-Ist - why is that? The negative of Cairo is that it will eat my long European destination for both tickets (I will arrive on a LONE4 from South America) and thus reduce my chance to earn mile by going to DBX. Are there any other things I should consider in this decision. I am also open to other suggestions on where to star my DONE4 trip. Thanks.