I was bored so I did the math and you are not correct. Even if you don't care about the people themselves, a normal citizen in an industrialized society like Israel has about 40 years of working life. Let's assume for simplicity that some rockets would hit children but others would hit retired people, on average hitting people when they're halfway through their career and would have 20 years of productive work left.
According to Wikipedia [1], Israel has an average GDP per capita of about 60 USD per hour worked, which at 40 hours per week, 50 weeks worked per year over 20 years comes to about 40000 hours of work and ~2.4 million USD of GDP generated. At an income tax of about 30% [2], that means an income for the state of about 800k USD equivalent. If the person dies due to rocket attack, the state would miss out on that. Iron dome interceptors are quite cheap compared to that and the laser intercepts should be an order of magnitude cheaper still.
This doesn't even take into account the sunk costs that industrialized nations incur by every citizen having to attend school for about the first two decades of their lives, mostly funded by the state. That represents a tremendous investment into human capital that would be lost if you let your citizens get shot up in preventable rocket attacks.
So no, human lives are not actually cheap when viewed through the lens of a country, even when completely excluding morals and only looking at it financially. They are in fact quite valuable.
[1] https://en.wikipedia.org/wiki/List_of_countries_by_labour_pr...
[2] https://en.wikipedia.org/wiki/Taxation_in_Israel#Income_tax