The advancement Star Trader can be cheesed by using an elevator.
1) Build a bubble elevator or a small flying machine. See screenshot.
2) Get a villager below the elevator and give them a workstation.
3) Jump into the bubble elevator and right click the villager at the same time, so while you stay inside the bubble elevator the villager UI is still open. It can be done even from height 0.
4) Buy or sell something at world height.