The Islamic Jihad-aligned Palestine Today site has an article that contrasts the cost to Israel of deploying Iron Dome to protect its citizens from attack, against the cost of Qassam rockets.
As they note, a Gaza rocket costs only between $100 (for a mortar) and $1000 (for a Grad,) while each Iron Dome interceptor rocket costs between $30,000-$40,000.
They seem amazed that Israel would care so much to defend its citizens from wanton attacks of rockets.
I'm sure that "human rights" organizations will find something to criticize about Iron Dome as soon as it is deployed. Maybe they will argue that Israel should spend its money instead to provide more aid to Gazans. Or that since Gazans have the "human right" of "resistance" that Israel doesn't have the right to stop it.