Another glitch with some deviously good benefits. Get another Jedi in your party and give them a Lightsaber. Hit the workbench and upgrade their lightsaber. Change the color crystal in the saber and press (X) to asssemble. Now select the saber again, go to the color crystal selection again, don't select one, just hit (X) again to assemble on the spot. You now have doubled that lightsaber.

Now SAVE then immediately RELOAD that save. This is critically important, as it turns it from a glitchy lightsaber (where if you remove something from one, it removes from its double) to a full fledged, real lightsaber.

To duplicate the Exile's lightsaber, simply have your companion use the workbench and do the trick as normal.

Extra lightsabers is neat and all, but the real purpose is to duplicate Crystals and Lenses/Emitters/Cells. And of course, an infinite item bug leads to extra money and components.