Well, for example, one idea is that whenever a crystal extractor is destroyed, the base production would decrease by 5% - for example, clean one is 0.4/sec, once destroyed and rebuilt is 0.38/sec, two times destroyed is 0.36/sec and so on.
You need to make a new ability to the crystal extractor. This ability will apply a buff to the crystal extractor, and this buff will apply a buff to the planet it orbits on death. The buff on the planet will have a periodic action that attempts to apply a buff to resource extractors every few seconds. This buff will decrease resource production by 5%. Just make sure to give all these buffs but the first one a high stacking limit like say 99 and set allowFirstSpawnerToStack to false.
The only problem with this is that A. This debuff will apply to all resource extractors, not just future extractors or the one destroyed, and not just crystal extractors. It would also apply to metal extractors. However, if you can get this working I can tell you how to get around that restriction.
That said, one problem with this ability is that it can only be done with that periodic action on the planet, and all else being equal you want to avoid using a lot of them since in large numbers they will lag the game. Still if this is important to you it will work.
You might find this helpful for figuring out the syntax for all of this.
