>>280190764
they're not worth it, maybe with the battery they're worth what they were asking before without the battery.
Unironically, a well fitting pair of stiff crocs are WAY better than foot straps. The hole in them allows for a proper bolt and washer, and they slip on and off, strap at the back and stay clean. Integrating a battery is dirt simple and you can even balance the weight that way.
As for a belt, just drill a hole in an old belt, washer, bolt, portable battery on usb, couple zip ties, done. 
The straps really aren't worth it and are less comfortable and functional. Takes me longer to put my hmd and index controllers on correctly then it does my fbt, which takes literally 5 seconds, slip shoes on, adjust belt, done.