Comment by tgtweak

You could reshingle a roof for $3.50/sqft and it's not unheard of to get traditional solar installed at $1.50/W, ~$15,000 for a 10kw system.

$7000 + $15,000

Then you apply the federal credit after that.

This is for a grid-tie system, I don't think Tesla is pricing theirs with a powerwall here.

Edit: apparently they're pricing it with 2 powerwalls, still cheaper by a sizeable margin however.