The Rediculousness Of "Value"
“Effort.” -Comes to mind.
http://www.youtube.com/watch?v=BwsH9Lc3qu8
Well…..not sure if people use cores for much else other than lodestone upgrading, but I would guess cores are less common than lodestones. Not saying they have a lower probability of dropping, but they are obtained from a lower level mob range no? Most people looking to get these materials are likely level 80, so they would be in level 80 zones (or the highest they can be for what they are going for) farming for lodestones, not cores.
I think it has more to do with the type of core/lodestone you are farming. From my experience corrupted lodestones are typically farmed/dropped in frostgorge from lvl 80 mobs. I have never had a corrupted core drop for me but have had about 12 lodestones so far. I’m assuming most people farming this type of lodestone would have experienced the same.
This is contrast to onyx cores/lodestones for example, in which the core is much more likely to drop from TA explorable chests rather than the lodestones, meaning that you can save money by buying cores and combining. However regardless of which method you chose to get your lodestones I doubt that the savings you would make reach 15% (TP tax)
That could be true hero, I have 40 corrupted lodestones, but have never gotten a corrupted core. Meanwhile, I have had roughly the same amount of glacial and molten lodestones/cores.