Whilst a commercial offering is probably quite expensive, it strikes me as the sort of thing you could do quite cheaply and easily with an arduino.

I've actually been collecting the vibration motors from disposable electric toothbrushes to build my own belt; as they were designed to run form a single AA battery powering them should be easy.

I find it quite expensive too. I guess the price is fair if you include the research they did, plus the prototyping, manufacturing and company overhead.

I've tried a prototype version of this belt once (for a couple of hours), it worked surprisingly well. But integrating the vibrations as a "new sense" into your brain (so that your subconscious can use it) takes at least some days.