It seems that a lot of items from past turn-in events can no longer be had, they became rares, thanks to the hoarding of sell-for-cash sites. Example: Chest of Heirlooms. It could be turned in 10 at a time for tokuno treasures. If you unlocked it however it could no longer be turned in and it makes a great storage container. I think if you vendor one it will be gone within minutes too thanks to those websites that monitor vendor contents.
It doesn't matter which server you vendor it on either, it will end up transferred, eventually.
I doubt any item from this doom set of turn-ins will become as valuable, but who knows. One drop off the lich in Ilsh is called a death vortex and even though it's still dropping its rare enough that it's on these sellers lists of items to look out for and so it sells for 50m+. In general if it sells for under 1m it's a common item, no matter where it comes from. The reason is that 1m is the value of a check and it's not worth holding onto an item worth less than that or you have 1 item space taken by something worth less than a check.
Anyway, the arties seem to be dropping again.