"worth stockpiling nickels at all?"
bad money drives out good
coinflation.com
$1 of nickels is worth $1.59 today
$1 of copper pennies 1982 or older are worth $3.12 for their metal content
it is not legal to melt them, but people are saving them like they do silver dimes quarters etc
you do not have to melt them to get the extra value
if metals go up then your spread on face value to metal will get larger
a nickel in your hand is still probably better than an "electric" one in a bank in new york
in 2011 investor kyle bass bought 20 million nickels