I’ve been toying with these little remote control model helicopters. They’re really fun and easy to mod. I started out by removing the vertical tail fin and canopy/cowling on mine. The weight reduction really helps the maneuverability and endurance.
To figure out the cost-benefit, I measured the mass of some of the sub-assemblies (including the screws, which each weigh about 0.05 g).
Cowling/canopy: 2.785 g
Vertical Tail Fin: 0.41 g
Tail rotor: 0.10 g
Skids: 2.04 g