The only way to extract cost 250 gems and we have never seen a perma-extractor in the gem store. Its never really worth it so we just end up overwriting and wasting runes/sigils. If we want to try new things it becomes so difficult.
Would it be possible to just remove the restriction alltogether? Free to extract runes/sigils? That would open the game up more. We have some new content coming and that would make it so much of a better experience considering the huge amount of new builds that are coming.