What's Fair Price for Shadow Ingot?

Dang...I just blew 15 billion to make 1 x LvL5 Diamond...
some 600 x LvL 1 Diamond I invested...and got 1 x LvL 4 left...ah well...

Anyways..
After the 11th anniversary event,
I got left with like 100+ shadow weapons and 500+ shadow enchant scrolls...

I could've sold them all to make some Adena, but I was curious about
shadow +10 weapon, so I thought I should go for it.


Well, I went for it all the way.

I enchanted all my shadow weapons and got like 10 x + 7 but I kept on
enchanting...Only 1 made it to +10.
+10 shadow slasher I got
800 damage, 15% increased attack speed, +100 critical.

I just learned that if I have 10 x shadow ingots, I can make it enhanced
even further with 875 damage, +10% NPC damage, + 7% damage increase.
(R99 Blessed Slasher has 800 damage)

The problem is 1 x shadow ingot is going for 500-600 Mil at Auction
House in my server, Chronos at the moment.

What is good price for shaodw ingots, guys?

I know shadow ingots you can only get from the new Gludio Instance
(a Level 99 requirement, but Level 100 hunting instance really...)
I heard it's so hard for LvL 99s to clear it.

but you can do the instance like 3 times a week
so...you can get 3 x shadow ingots a week if you are lucky....

;and I don't think there are many +10 shadow weapons out there...
Enchant failure rate is much higher for shadow weapons than
regular weapons...

but shadow ingots, people will be getting more and more...
more and more people hitting level 100 as time passes by...

Anyways, if I want to make the enhanced shadow slasher now,
it's gonna cost me 5 billion adena just for the ingots....
(initially I thought 1 x ingot = 100-200 Million...ah well lol)

What's good and fair price for shadow ingots, guys?
It took 100 + shadow weapons + enchant scrolls
to make 1 x +10 shadow weapon...

and what will be the good price for enhanced shadow weapons if I want
to buy or sell them in future?

Looking for some educated advice on pricing
from the experienced players here....