B&H Photo Video offers preorders of the Feiyu WG2 Wearable/Mountable Gimbal for GoPro for $247 with free shipping. That's the lowest price we could find by $52. It's compatible with HERO5 and similar-size cameras and features 360° pan and tilt, 70° roll angle rotation, auto-rotation mode, 2.5-hour battery life, and splashproof design. Deal ends June 28.
Note: It's unclear when this item will ship.