Round-trip: $800
One-way: $2000 (or $4k for two one-ways to make up a round-trip)
I don’t know why anyone would ever book a one-way. It’s insanity.
It’s a real pain, and makes it harder to create your own open-jaw when the airline doesn’t serve all 3 cities.
What ends up happening is I book through other airlines entirely that don’t pull these shenanigans.
This is actually an interesting problem in the crypto space as well with things like remittances.
Since she hates stuff like this, I was tasked with finding a cheap tickets. For the first trip from here in Norway to the west-African country, I found that the cheapest tickets were from KLM (who flew direct from Amsterdam, so only one stop), and the round-trip ticket was indeed about $300 cheaper than a one-way ticket.