I'll take a stab at it; expensive and we are.
Another question worth exploring is how did he pay for the ticket? The per capita annual income of Liberia is about $800. A last minute ticket to the US is probably about $2000. What were the source of the funds? Did his family here in the US pay for the ticket? Did they do so knowing that he was sick, and needing treatment?
I don't honestly know the answer to this but it's important to realize that not everyone in Africa is dirt-poor. They just have a huge income gap with a small handful of people at the top, politically connected, who are wildly rich and vast swaths at the bottom who subsist on virtually nothing. What Africa does not have is a middle class. It's quite possible that Duncan was one of Africa's "one percenters" with the means to travel here in an effort to save his own life.
A clerk at a FedEx agency doesn’t sound like a one-percenter.