Updated The Fitbit Versa is cheaper than the Ionic, yet has almost as many features and a better design.
Updated The Fitbit Charge 3 strikes a good balance between price and features, but it's not for everyone.
Updated The Bose Sleepbuds do what they're designed to, effectively masking noise, but they're not cheap.
In depth 3D goggles didn't work in the cinema, but VR headsets might. Just don't expect them any time soon...