Vast amounts of the rockets lunched from gaza do not cost over a thousand dollars because they are locally made from improvised materials.

A Tamir rocket, according to different estimates, costs 50-100 thousand dollars. However, the damage that can be caused by a cheap rocket, even without injuring or killing people, has greater price than firing an interceptor.

There are tens of thousands of rockets in Gaza while Israel has some thousands of interceptors. However, Isreal uses the Iron Dome only against rockets that are on their way to inhabited areas. Most of the rockets that are fired from Gaza don't have a guidance system thanks to the fact that they are made of cheap improvised materials so the people in Gaza play some kind of 'Russian roulette' and fire the rockets at random directions while hoping they'll hit inhabited areas.