Other Middle East and Africa Frequent Flyer Programs - Ethiopian Air Allow Buy-Up to Biz?

Hello. . . I am looking at some award itineraries from the U.S. to Asia with a stopover, and one stopover city I'm considering Addis Ababa. I can find plenty of economy award availability on Ethiopian Air, but not biz award availability. Does anyone know if Ethiopian Air will let you buy up from economy to business class at the airport? If so, anyone have any price and availability info? Many thanks.

I wouldn't count on any non-US based airline to offer a buy up on an award ticket.