UPDATED: Price Reduced to 15b
Some background on this skin:
The Nyx Umbral SKIN was distributed in 2015 to players who pre-ordered the $1800 Floating Nyx Model that was never shipped. When it was announced that the Floating Nyx would never be manufactured, the SKIN was offered as a consolation to those who spent $100 to pre-order the model. Only 500 pre-orders were taken, and presumably fewer of the codes were ever actually activated. As a result, there were very few of these ever present in the game.
At present there is one available on the market for 40b ISK. Market data does not exist for this item as one has not changed hands outside of private contracts for several years. The most “recent” confirmed sale I could identify placed the value at 25b over three years ago.
Nyx Umbral Skin (Permanent) - 15b
Located in Jita, can be activated from anywhere
(Also open to trade for ships/mods/etc)