So they raised the fuel needed for flights after 5 days. Another 5 days will be up in about 4 hours, wonder if they are going to jack the cost per flight again. I'm hopeful they won't as the first time was a pretty substantial amount. I can't imagine using 80 fuel or so for just one flight.
I am assuming just like the Age of Ash event, the fuel needed will increase as we get closer to the end. I don't remember what the final bonus fuel was for it, but I imagine this will be similar.