supposition - ESO want to promote people doing daily crafting quests. So occasionally I have to buy Rubedite for crafting weapons heavy armor. I can purchase any quantity from any Guild trader for a reasonable amount of Gold.
The Oko runestone is a real PIA for a variety of reasons.
- I have 15 active characters. Daily I get 15 enchanter bundles from Enchanter Hirelings (3/3) Daily haul 6 Rekuta (a purple, supposedly rarer glyph and 1 Oko runestone makes no sense
- The OKO glyph is required for 62% of all Enchanting Dailies, while there are a total of 17 runestone of the Essence class not counting the Hakeijo runestone. That also makes no sense.
- When doing enchanter surveys, out of 6 piles, 1 Oko runestone is found. So doing enchanter surveys is not a very effective way of accumulating the Oko runestone.
- So a level 50 character can buy a Monumental glyph of Health for 262 gold. I have averaged a 30% extraction rate for the the Oko runestone or a cost of 873 gold each for Oko runestone. Now if I have a level 3 character I can buy a lesser glyph of health for 75 gold or a cost of 250 gold for each Oko runestone. So I have to maintain a level 3 character to effect the cost savings.
- Obviously I can purchase from a Guild store but few traders have Oko runestones avail or avail in quantities of 200.
With current drop rates I have to buy or make 90% of the Oko runestones that I need. I don't think that is consistent with ESO's outlook toward daily crafting quests. To me requiring the OKO runestone in 62% of the enchanting quests was never considered.