A pistol grip is not an expensive item per-se (the great handle from P&C, for example, is about $19), but I love the idea behind it and I think a similar mechanism can definitely be used for other builds as well. And besides, who can resist the chance to dissect a lil girl jump rope.
If you ever tried to shoot video with a DSLR, you’ve probably noticed how quickly your wrist starts to heart. This happen because camera grips were not designed for video. A camera pistol grip changes your hand orientation while holding the camera to a more natural position do it does not get soar after a while. (Kinda similar to how you hold a pistol, hence the name).