To quote Byrth's posts from another forum:

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With 9 Heavy Metal Plates per pouch average, 6% chance of pouch drops, that works out to 0.54 plates per Zilart VW T3 kill.
Kaggen/Pil/Akvan are 0.35 plates/kill and drop crafting materials for armor upgrades.
Morta/Bismarck are 0.13 plates/kill but also drop Rift items 6% of the time and crafting materials

It takes roughly 3500 Voidstones to farm a 99 Empyrean. At 2 voidstone recharges/day, that's 4.8 years worth of voidstones on one character. Clears (before the voidwatch time reducing KIs), a little squandering here and there, and you're up near 5 years worth of voidstone recharges.

Voidwatch has been out since May of 2011. Congrats to anyone who has been saving up stones since then because you can finally solo a level 99 Empyrean without buying anything or making a second account.
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How can you look at those numbers, then look at the state of the game today, and not see how ridiculously unbalanced the quest for 99 Empyrean weapons is?