The value of a used 24 KWh battery used in, say, an old EV non-tesla car - $2000 (note this still has plenty of life left). Example: a 2013 Nissan Leaf
The value of the same, repurposed to a "powerwall" - $10k per 10 KWh
The value of it once attached to a "movable powerwall" - :) add a few more zeros