Paying it forward!

[Ferra]

Shaded Spectacle is made from two Polarized Glass
https://ffxiv.gamerescape.com/wiki/Polarized_Glass
It is rare drop from only two submersible destinations or chests from a Leather Buried Treasure Map, obtained from an Unhidden Leather Map which itself is a very rare drop from any ARR/HW chest found by ARR/HW Timeworn Treasure Maps.

So a drop from a specific item followed by another drop followed by another drop...

...Yeah, I can see the reasoning for the pricing!