When Israel blockades Gaza they create an incentive for Hamas aligned groups to develop technologies that shouldn't exist – like DIY weaponized rocketry.
Gaza: How the resistance manufactures its rockets with help from Iran, Syria, and Hezbollah
Leading figures in the Palestinian resistance explained the difference in cost between manufacturing rockets locally and smuggling them from Iran. They said, “Locally made rockets are almost as powerful as smuggled ones, but cost less. The cost of a rocket like the one used to bomb Tel Aviv does not exceed $5,000, while a smuggled rocket may cost up to $15,000.” Regarding short-range rockets, for example, the cost of a smuggled 107-type rocket is around $800, while the same rocket can be made locally for $110.