After a 13 mile run down to Walmart, had a $1 sandal & 2x6 ft shoelaces.  Should have gotten more than 1 sandal, since it wasn't the price but the run that was the mane cost.  The $1 sandal was just a piece of foam with a strap.  It wouldn't last very long, but the lion kingdom mused at how it was what used to be the more expensive model at Costco, many decades ago.  The xeroshoes.com & 

lunasandals.com were truly complete ripoffs.

The mane problem with Huarache sandals is the knot under the toes.  It would be nice to use the existing strap to avoid having to tie the dreaded knot, but the $1 sandals were just a proof of concept & the straps were worthless. 

Using this video

yielded this:

Everything was a bit too close to the front, but bearable.  The foam slabs went from flopping to being firmly attached to the paws, except for the toes wanting to slide forward.  The weather won't be warm enough for a test for several weeks.

Getting the right tension, hole positions, & foam size is an artform.  This is where the $70-$200 could make a difference.  They come off & go on as easily as shoes.  They wouldn't stay tied in packed luggage.