My own drone only took a little bit of assembly, so it was very easy! But you can get some very complex kits with lots of fancy functions.
The kits I would make with the prize money would be a little more complex, just to make your grey matter work a bit! Ideally there would be a bit of mechanical and a bit of electrical assembly, and even the potential for some programming too but I’d need to see how it all fits together into the task!
Do you have a drone yourself or have you ever flown a drone?