James Young's life was changed after a train accident took away his arm and leg. Now, thanks to the help of Konami, he's getting back on track with an arm inspired by Metal Gear Solid V. The arm comes in at around $100,000 to make, which Konami funded $60,000 of according to Geeks Are Sexy.
In this 2 part documentary, you'll see the arms creation from start to end. If you're just looking for arm action, you might want to skip to around 10 minutes into part one as that's when you start to see it in action.
Is the arm effective? The pros are it has a built in USB charger and drone. The cons are it's heavy, can't lift a ton of weight, and doesn't always work the way it should. It's still in development, of course, so hopefully it only gets better!