In Star Wars, the Rebel Alliance thought they were doing a good thing by destroying the Death Star. Little did they know the unintended consequences its destruction would have—notably, the complete and utter collapse of the Galactic Empire's economy.
The building of the death star would have sunk the star wars economy. The death star was a planet sized gun, wasn't it? If so, every dime spent on it was essentially thrown away in an effort to throw away even more money as it blew up planets. Unless it was a big factory, the empire's economy was screwed anyways. Destroying a weapon doesn't hurt an economy, it helps it. In fact, the scrap from the death star would re-allocate those resources and help revitalize an economy harmed to build the thing in the first place. Of course, I'm no economist.
These small cities exist at the expense of a higher tax rate, and due to this, exist at the reduction of the efficiency and productivity of the entire economy. So far as I know economics, if these people weren't making weapons, if they were building roads, or anything else, the economy would be stronger. If these people were out of the job, the economy would be stronger. Overall, the weapons manufacture, unless those weapons create higher levels of stability in the long run, is a waste of resources and energy. And the economy would be better off if they were instead trying to build better consumer aircraft and other luxuries. It's in space, in an era where space travel is regular. Space isn't like the ocean, it doesn't sink to the bottom, it remains as accessible as just about anything else would in the area. And this is a planet-sized craft being blown up, not just some boat or something.There are several, probably hundreds of small cities in America who would suffer a total economic collapse if not for military spending.
There are large research and development groups at all of the major aerospace companies that employ skilled laborers who produce new technologies that are often useful outside of blowing people up.
Also, the scrap metal from the exploded death star is likely in the same economic position as the gold on the bottom of the sea: it would cost far more to harvest it than it could be sold for.
It also wouldn't just be metal. If there really was a shortage, the transport would likely be cheap enough to justify the costs. Rare metals, plastics, advanced scifi-materials that takes a massive amount of processing, all may be in low weight, high cost, easy to transport situations.