You missed the point: Abbas does not represent the Palestinian people. You know it, I know it, the Pals know it, the world knows it. You might as well negotiate on behalf of the Palestinians with the Chinese. As for saving money, on a theoretical basis, it could. But in practice, it's a huge vulnerability. You are basically tossing up $40-50K rockets (and several) to shoot down a few glorified pipe rockets consisting of basic fuel and old metal (some don't even have explosives). Like I said, policies WILL be enacted to exploit this disparity, and the theoretics of your cost-saving will become meaningless.
Man shot dead in northern Israel town of Bi'ina, police say the murder was gang related (Haaretz)
from the article: Iron Dome success excites, but army balks at the bill