Talk:Dungeon/@comment-71.202.182.150-20190412003222/@comment-71.202.182.150-20190415122614

It looks like the pattern is that the removal cost doubles with each tier. So "chipped" costs 10 gems to remove and save, "shard" costs 20, "polished" costs 40, "regular" costs 80, and "pure" costs 160 gems. If that pattern holds, then the remaining 5 tiers cost 320, 640, 1280, 2560, and 5120 gems, respectively to remove. Even if you want to spend gems toward stones, dungeon keys seem the better value until fairly far along. At the later dungeon stages you can nearly get a new "regular" gem for every 10 gems, whereas simply retrieving one you're already using costs 80 gems. You'd need to be working on "flawless" or higher in order to actually save from removing versus buying dungeon keys in this way (it costs 640 gems to retrieve a used "flawless" gem, which is the same number of gems needed to make a new one from scratch through bought keys with lots of gold added on top).

So, in general, the long-term strategy seems to be to never retrieve stones unless they are "flawless" or better (unless you're happy essentially spending gems to save gold). So, any pre-flawless stones socketed to satisfy event quests are being sacrificed for those quests.